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Journal articles on the topic 'Stereo- and regioselectivity'

Author: Grafiati

Published: 4 June 2021

Last updated: 12 February 2022

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1

Goux, Catherine, Magali Massacret, Paul Lhoste, and Denis Sinou. "Stereo- and Regioselectivity in Palladium-Catalyzed Allylic Etherification." Organometallics 14, no. 10 (October 1995): 4585–93. http://dx.doi.org/10.1021/om00010a024.

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2

Cacchi, Sandro, Giancarlo Fabrizi, Andrea Fochetti, Francesca Ghirga, Antonella Goggiamani, and Antonia Iazzetti. "Stereo- and regioselective gold(i)-catalyzed hydroamination of 2-(arylethynyl)pyridines with anilines." Organic & Biomolecular Chemistry 17, no. 3 (2019): 527–32. http://dx.doi.org/10.1039/c8ob02356e.

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3

Okoromoba, Otome E., Zhou Li, Nicole Robertson, Mark S. Mashuta, Uenifer R. Couto, Cláudio F. Tormena, Bo Xu, and Gerald B. Hammond. "Achieving regio- and stereo-control in the fluorination of aziridines under acidic conditions." Chemical Communications 52, no. 91 (2016): 13353–56. http://dx.doi.org/10.1039/c6cc07855a.

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DMPU–HF demonstrates good reactivity and regioselectivity in conversion of aziridines into biologically important β-fluoroamines. The stereochemistry of aziridine-opening was found to be depend greatly on substitution pattern.

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4

GOUX, C., M. MASSACRET, P. LHOSTE, and D. SINOU. "ChemInform Abstract: Stereo- and Regioselectivity in Palladium-Catalyzed Allylic Etherification." ChemInform 27, no. 6 (August 12, 2010): no. http://dx.doi.org/10.1002/chin.199606127.

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5

Xiong, Yiwen, Ping Qian, Chenhui Cao, Haibo Mei, Jianlin Han, Guigen Li, and Yi Pan. "One-pot stereoselective synthesis of α,β-differentiated diamino esters via the sequence of aminochlorination, aziridination and intermolecular SN2 reaction." Beilstein Journal of Organic Chemistry 10 (August 7, 2014): 1802–7. http://dx.doi.org/10.3762/bjoc.10.189.

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We report here an efficient one-pot method for the synthesis of α,β-differentiated diamino esters directly from cinnamate esters using N,N-dichloro-p-toluenesulfonamide and benzylamine as nitrogen sources. The key transformations include a Cu-catalyzed aminohalogenation and aziridination, followed by an intermolecular SN2 nucleophilic ring opening by benzylamine. The reactions feature a wide scope of substrates and proceed with excellent stereo- and regioselectivity (anti:syn >99:1) .

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6

Di Pietro, Sebastiano, Vittorio Bordoni, Andrea Mezzetta, Cinzia Chiappe, Giovanni Signore, Lorenzo Guazzelli, and Valeria Di Bussolo. "Remarkable Effect of [Li(G4)]TFSI Solvate Ionic Liquid (SIL) on the Regio- and Stereoselective Ring Opening of α-Gluco Carbasugar 1,2-Epoxides." Molecules 24, no. 16 (August 14, 2019): 2946. http://dx.doi.org/10.3390/molecules24162946.

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Carba analogues of biologically relevant natural carbohydrates are promising structures for the development of future drugs endowed with enhanced hydrolytic stability. An open synthetic challenge in this field is the optimization of new methodologies for the stereo- and regioselective opening of α-gluco carbasugar 1,2-epoxides that allow for the preparation of pseudo mono- and disaccharides of great interest. Therefore, we investigated the effect of Lewis acids and solvate ionic liquids (SILs) on the epoxide ring opening of a model substrate. Of particular interest was the complete stereo- and regioselectivity, albeit limited to simple nucleophiles, toward the desired C(1) isomer that was observed using LiClO4. The results obtained with SILs were also remarkable. In particular, Li[NTf2]/tetraglyme ([Li(G4)]TFSI) was able to function as a Lewis acid and to direct the attack of the nucleophile preferentially at the pseudo anomeric position, even with a more complex and synthetically interesting nucleophile. The regioselectivity observed for LiClO4 and [Li(G4)]TFSI was tentatively ascribed to the formation of a bidentate chelating system, which changed the conformational equilibrium and ultimately permitted a trans-diaxial attack on C(1). To the best of our knowledge, we report here the first case in which SILs were successfully employed in a ring-opening process of epoxides.

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7

Ranu, Brindaban C., Laksmikanta Adak, and Subhash Banerjee. "Efficient regio- and stereo-selective cleavage of aziridines and epoxides using an ionic liquid as reagent and reaction medium." Canadian Journal of Chemistry 85, no. 5 (May 1, 2007): 366–71. http://dx.doi.org/10.1139/v07-040.

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Ionic liquids, containing a variety of functionalities such as halo, azido, and thiocyano, efficiently cleave aziridines and epoxides to the corresponding products in high yields. The cleavages are regio- and stereo-selective. The reactions are complete in 1 h at 60 °C and do not require any other catalyst or organic solvent. Thus, a convenient synthetic route to 1,2-haloamines, 1,2-azidoamines, 1,2-thiocyanoamines, 1,2-azidoalcohols, and 1,2-thiocyanoalcohols is developed.Key words: aziridine, epoxide, ionic liquid, cleavage, regioselectivity, stereoselectivity

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8

Lafuente, Leticia, María Florencia Rochetti, Rodolfo Bravo, Leandro Sasiambarrena, Cintia C. Santiago, and Agustín Ponzinibbio. "Cu-Fe Spinels: First Heterogeneous and Magnetically Recoverable Catalyst for the Ferrier Rearrangement of 2-Nitroglycals." Letters in Organic Chemistry 16, no. 6 (April 23, 2019): 447–53. http://dx.doi.org/10.2174/1570178615666181022145338.

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Cu-Fe spinels promoted the Ferrier rearrangement of 2-nitroglycals with several O-nucleophiles. 2,3-Unsaturated carbohydrate derivatives were prepared by the reaction of 3,4,6-tri-Oacetyl- 2-nitroglucal and alcohols in the presence of 5 % of CuFe2O4. After separation of the catalyst with an external magnet, the reaction products were obtained in good yields and high stereo and regioselectivity. Also, S- and heterocyclic C-3 substituted 2-nitro-endo-glycals could be prepared by this method.

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9

Gutman, Arie L., Marina Etinger, Gennady Nisnevich, and Felix Polyak. "Stereo- and regioselectivity in asymmetric synthesis of α-amino substituted benzocyclic compounds." Tetrahedron: Asymmetry 9, no. 24 (December 1998): 4369–79. http://dx.doi.org/10.1016/s0957-4166(98)00467-4.

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10

Bodnar, Paul M., Wylie S. Palmer, Brian H. Ridgway, Jared T. Shaw, Jacqueline H. Smitrovich, and K. A. Woerpel. "Stereo- and Regioselectivity of Reactions of Siliranes with Aldehydes and Related Substrates." Journal of Organic Chemistry 62, no. 14 (July 1997): 4737–45. http://dx.doi.org/10.1021/jo970263k.

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11

TAKAHASHI, Hidetaka, Kouichi OHE, Sakae UEMURA, and Nobuyuki SUGITA. "Stereo- and regioselectivity in the addition of benzenetellurolate ion to triple bond." NIPPON KAGAKU KAISHI, no. 7 (1987): 1508–11. http://dx.doi.org/10.1246/nikkashi.1987.1508.

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12

Brulíková, Lucie, Aidan Harrison, Marvin J. Miller, and Jan Hlaváč. "Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes." Beilstein Journal of Organic Chemistry 12 (September 1, 2016): 1949–80. http://dx.doi.org/10.3762/bjoc.12.184.

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The hetero-Diels–Alder reaction between a nitroso dienophile and a conjugated diene to give the 3,6-dihydro-2H-1,2-oxazine scaffold is useful for the synthesis of many biologically interesting molecules due to the diverse opportunities created by subsequent transformations of the resulting 1,2-oxazine ring. This review discusses the rationale for the observed regio- and stereoselectivity and the methods developed in recent years used to control and improve the stereo- and regioselectivity for the synthesis of 1,2-oxazine scaffolds.

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13

Wang, Hongwei, Hongchen Li, Guoqi Yu, Yun-Bing Zhou, Yalong Bai, Yanling Hei, and Junwei Chen. "Synthesis of β-Hydroxy Aryl Selenides via Transition-Metal-Free Three-Component Reaction of Arylamines, Elemental Selenium, and Epoxides." Synthesis 53, no. 19 (May 5, 2021): 3621–29. http://dx.doi.org/10.1055/a-1499-8742.

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AbstractAn efficient protocol for the construction of valuable β-hydroxy aryl selenides from easily available arylamines, elemental selenium, and epoxides through a transition-metal-free radical process is described. A wide variety of β-hydroxy aryl selenides were obtained in good to excellent yields with excellent stereo- and regioselectivity. In this reaction, two C–Se bonds can be built along with the cleavage of a C–N and C–O bond, demonstrating the high step economy and efficiency of this approach.

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14

Yang, Xiang-Yuan, Jun Hao Gan, Yongxin Li, Sumod A. Pullarkat, and Pak-Hing Leung. "Palladium catalyzed asymmetric hydrophosphination of α,β- and α,β,γ,δ-unsaturated malonate esters – efficient control of reactivity, stereo- and regio-selectivity." Dalton Transactions 44, no. 3 (2015): 1258–63. http://dx.doi.org/10.1039/c4dt02673j.

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15

Zhu, Wei, Bao Wang, Shengbin Zhou, and Hong Liu. "The facile construction of the phthalazin-1(2H)-one scaffold via copper-mediated C–H(sp2)/C–H(sp) coupling under mild conditions." Beilstein Journal of Organic Chemistry 11 (September 14, 2015): 1624–31. http://dx.doi.org/10.3762/bjoc.11.177.

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A novel strategy for the construction of the phthalazin-1(2H)-one scaffold has been developed by means of a copper-mediated cascade C–H/C–H coupling and intramolecular annulations and a subsequent facile hydrazinolysis. This C–H activation transformation proceeds smoothly with wide generality, good functional tolerance and high stereo- and regioselectivity under mild conditions. Through the removal of the directing group, the resulting moiety could easily be transformed into the phthalazin-1(2H)-one scaffold, which is known to be a privileged moiety and a bioactive nucleus in pharmaceuticals.

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16

Roiban, Gheorghe-Doru, Rubén Agudo, and Manfred T. Reetz. "Stereo- and regioselectivity in the P450-catalyzed oxidative tandem difunctionalization of 1-methylcyclohexene." Tetrahedron 69, no. 26 (July 2013): 5306–11. http://dx.doi.org/10.1016/j.tet.2013.04.132.

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17

Boonyarattanakalin, Siwarutt, Somsak Ruchirawat, and M. Paul Gleeson. "Ring opening polymerization of mannosyl tricyclic orthoesters: rationalising the stereo and regioselectivity of glycosidic bond formation using quantum chemical calculations." MedChemComm 4, no. 1 (2013): 265–68. http://dx.doi.org/10.1039/c2md20178j.

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Quantum chemical methods have been used to assess the physico-chemical origin of the stereo and regio-selectivity during glycosyl tricyclic orthoester polymerization. The subtle modulation of steric and electronic factors dramatically influences the reaction.

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18

Kalena, Govind P., Padmanava Pradhan, and Asoke Banerji. "Stereo- and regioselectivity of intramolecular 1,2-arene-alkene photocycloaddition in 2-alkenyl-4-chromanones." Tetrahedron 55, no. 11 (March 1999): 3209–18. http://dx.doi.org/10.1016/s0040-4020(98)01134-x.

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19

Röll, Werner, Hans-Herbert Brintzinger, Bernhard Rieger, and Ralf Zolk. "Stereo- and Regioselectivity of Chiral, Alkyl-substitutedansa-Zirconocene Catalysts in Methylalumoxane-activated Propene Polymerization." Angewandte Chemie International Edition in English 29, no. 3 (March 1990): 279–80. http://dx.doi.org/10.1002/anie.199002791.

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20

BODNAR, P. M., W. S. PALMER, B. H. RIDGWAY, J. T. SHAW, J. H. SMITROVICH, and K. A. WOERPEL. "ChemInform Abstract: Stereo- and Regioselectivity of Reactions of Siliranes with Aldehydes and Related Substrates." ChemInform 28, no. 49 (August 2, 2010): no. http://dx.doi.org/10.1002/chin.199749187.

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21

Gutman, Arie L., Marina Etinger, Gennady Nisnevich, and Felix Polyak. "ChemInform Abstract: Stereo- and Regioselectivity in Asymmetric Synthesis of α-Amino Substituted Benzocyclic Compounds." ChemInform 30, no. 28 (June 14, 2010): no. http://dx.doi.org/10.1002/chin.199928127.

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22

Champreda, Verawat, Young-Jun Choi, Ning-Yi Zhou, and David J. Leak. "Alteration of the stereo- and regioselectivity of alkene monooxygenase based on coupling protein interactions." Applied Microbiology and Biotechnology 71, no. 6 (January 10, 2006): 840–47. http://dx.doi.org/10.1007/s00253-005-0208-2.

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23

Xu, Jinqi, Mathew George, and Richard G. Weiss. "Photo-Fries rearrangements of 1-naphthyl (R)-2-phenylpropanoate in poly(vinyl acetate) and ethyl acetate: influence of medium polarity and polymer relaxation on motions of singlet radical pairs." Anais da Academia Brasileira de Ciências 78, no. 1 (March 2006): 31–44. http://dx.doi.org/10.1590/s0001-37652006000100005.

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Both the regio- and stereo-chemistries of the photoreactions of 1-naphthyl (R)-2-phenylpropanoate have been investigated in poly(vinyl acetate) films in their glassy (at 5ºC) and melted (at 50ºC) states and in ethyl acetate. These results are compared with those from irradiations in polyethylene films and in n-hexane. The regioselectivity of the intermediate 1-naphthoxy/(R)-2-phenylpropanoyl radical pair combinations is much higher in both the melt and glassy states of poly(vinyl acetate) films than that in the melt state of completely amorphous polyethylene films, but the stereoselectivity of intermediate prochiral 1-naphthoxy/1-phenylethyl radical pair combinations is much lower in poly(vinyl acetate). The results emphasize the need to control the ratio between the rates of radical tumbling and translation, as well as the ratio between the rates of in-cage motions and cage-escape, if high stereo- and regio-selectivities of combination products are to be achieved. A mechanistic picture of how the radicals of the intermediate pairs are affected by and interact with the various media is advanced.

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24

Guerra, Gaetano, Paolo Corradini, and Luigi Cavallo. "Molecular Modeling of Stereo- and Regioselectivity of Group 4 Heterocenes in the Polymerization of Propene." Macromolecules 38, no. 9 (May 2005): 3973–76. http://dx.doi.org/10.1021/ma047651q.

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25

Zwick, Jean-Christophe, Pierre Voge, Vladimir Mange, and Gervals Chapuis. "Control ofDiels-Alder Addition, Stereo- and Regioselectivity by Remote Substituents and Tricarbonyl(diene)iron Moieties." Helvetica Chimica Acta 70, no. 5 (August 12, 1987): 1231–49. http://dx.doi.org/10.1002/hlca.19870700502.

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26

Bravo, Fernando, Frank E. McDonald, Wade A. Neiwert, Bao Do, and Kenneth I. Hardcastle. "Biomimetic Synthesis of Fused Polypyrans: Oxacyclization Stereo- and Regioselectivity Is a Function of the Nucleophile†." Organic Letters 5, no. 12 (June 2003): 2123–26. http://dx.doi.org/10.1021/ol034539o.

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27

De, Sriman, Eti Mahal, Md Ashraful Haque, Chandan K. Jana, and Debasis Koley. "Computational Investigation of Multifaceted Cationic Rearrangement and Stereo- and Regioselectivity in the Formation of Dysideanone’s Analogues." Journal of Organic Chemistry 86, no. 1 (December 17, 2020): 1133–40. http://dx.doi.org/10.1021/acs.joc.0c02609.

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28

Smith, Nicole M., K. Swaminathan Iyer, and Ben Corry. "The confined space inside carbon nanotubes can dictate the stereo- and regioselectivity of Diels–Alder reactions." Physical Chemistry Chemical Physics 16, no. 15 (2014): 6986. http://dx.doi.org/10.1039/c3cp54295e.

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29

Crociani, Bruno, Simonetta Antonaroli, Francesca Di Bianca, and Alberta Fontana. "Stereo and regioselectivity in the phenylation of cationic allylpalladium(II) α-diimine complexes by tetraphenylborate anion." Journal of Organometallic Chemistry 450, no. 1-2 (May 1993): 21–26. http://dx.doi.org/10.1016/0022-328x(93)80131-t.

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30

Bansal, Raj K., Vimal K. Jain, Neelima Gupta, Nidhi Gupta, Leena Hemrajani, Mukta Baweja, and Peter G. Jones. "Stereo- and regioselectivity in Diels–Alder reactions of 1,3-azaphospholo[5,1-a]isoquinoline and -[1,5-a]pyridine." Tetrahedron 58, no. 8 (February 2002): 1573–79. http://dx.doi.org/10.1016/s0040-4020(02)00004-2.

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31

Rüedi, Georg, Matthias Nagel, and Hans-Jürgen Hansen. "Stereo- and Regioselectivity in Dynamic Gas-Phase Thermoisomerization (DGPTI): Novel Route to α-Campholanic Acid and Derivatives." Organic Letters 5, no. 15 (July 2003): 2691–93. http://dx.doi.org/10.1021/ol034882t.

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32

Miller, Kristy K. Michael, Jian Cai, Sharon L. Ripp, William M. Pierce, Thomas H. Rushmore, and Russell A. Prough. "STEREO- AND REGIOSELECTIVITY ACCOUNT FOR THE DIVERSITY OF DEHYDROEPIANDROSTERONE (DHEA) METABOLITES PRODUCED BY LIVER MICROSOMAL CYTOCHROMES P450." Drug Metabolism and Disposition 32, no. 3 (February 20, 2004): 305–13. http://dx.doi.org/10.1124/dmd.32.3.305.

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33

Dayer, P., T. Leemann, A. K�pfer, T. Kronbach, and U. A. Meyer. "Stereo- and regioselectivity of hepatic oxidation in man ? Effect of the debrisoquine/sparteine phenotype on bufuralol hydroxylation." European Journal of Clinical Pharmacology 31, no. 3 (1986): 313–18. http://dx.doi.org/10.1007/bf00981130.

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34

Crotti, Paolo, Fabrizio Badalassi, Valeria Di Bussolo, Lucilla Favero, and Mauro Pineschi. "Stereo- and regioselectivity of cyclization reactions in conformationally restricted epoxy ketones: evaluation of C- versus O-alkylation process." Tetrahedron 57, no. 40 (October 2001): 8559–72. http://dx.doi.org/10.1016/s0040-4020(01)00817-1.

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35

Shing, Tony K M., Wai F Wong, Taketo Ikeno, and Tohru Yamada. "Stereo- and Regioselectivity in an Intramolecular Nitrone-Alkene Cycloaddition of Hept-6-enoses with atrans-Acetonide Blocking Group." Chemistry - A European Journal 15, no. 11 (March 2, 2009): 2693–707. http://dx.doi.org/10.1002/chem.200800867.

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36

Domingo, Luis R., M. Teresa Picher, Juan Andrés, and Vicent S. Safont. "Ab InitioStudy of Stereo- and Regioselectivity in the Diels−Alder Reaction between 2-Phenylcyclopentadiene and α-(Methylthio)acrylonitrile." Journal of Organic Chemistry 62, no. 6 (March 1997): 1775–78. http://dx.doi.org/10.1021/jo961785n.

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37

Eichmann, Thomas O., Manju Kumari, Joel T. Haas, Robert V. Farese, Robert Zimmermann, Achim Lass, and Rudolf Zechner. "Studies on the Substrate and Stereo/Regioselectivity of Adipose Triglyceride Lipase, Hormone-sensitive Lipase, and Diacylglycerol-O-acyltransferases." Journal of Biological Chemistry 287, no. 49 (October 12, 2012): 41446–57. http://dx.doi.org/10.1074/jbc.m112.400416.

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38

Ruffoni, Alessandro, Alessandro Casoni, Maria Luisa Gelmi, Sara Pellegrino, and Francesca Clerici. "Hydroarylation of Substituted Norbornene Amino Acids: Studies on Long-Range Stereo-Electronic Effects on the Regioselectivity of the Addition." Current Organic Chemistry 16, no. 22 (November 1, 2012): 2724–38. http://dx.doi.org/10.2174/138527212804004472.

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39

Vo, Loan K., and Daniel A. Singleton. "Isotope Effects and the Nature of Stereo- and Regioselectivity in Hydroaminations of Vinylarenes Catalyzed by Palladium(II)−Diphosphine Complexes." Organic Letters 6, no. 14 (July 2004): 2469–72. http://dx.doi.org/10.1021/ol049137a.

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40

Demeter, Fruzsina, Tímea Balogh, Tse-Kai Fu, Margaret Dah-Tsyr Chang, Yuan-Chuan Lee, Anikó Borbás, and Mihály Herczeg. "Preparation of α-l-Rhamnobiosides by Open and Conventional Glycosylations for Studies of the rHPL Lectin." Synlett 30, no. 19 (October 10, 2019): 2185–92. http://dx.doi.org/10.1055/s-0039-1690710.

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To study the effect of oligosaccharides on biological systems (e.g., carbohydrate–lectin interactions), chemical synthesis of the desired carbohydrate derivatives is highly desirable, but it is usually a very complicated task. Most of the stereo- and regioselective glycosylation reactions are carried out by using protected acceptors and donors. At the same time, open glycosylation (use of an unprotected acceptor) may shorten the reaction pathway, if sufficient selectivity can be achieved between the acceptor hydroxyl groups. Toward synthesis of higher oligomers and multivalent derivatives, which are often useful for lectin binding studies, open glycosylation reactions of propargyl and phenylthio rhamnosides were investigated as a rapid route to the α-(1,3)-linked rhamnobioside binding motif. The efficacy of open glycosylations proved to be highly dependent on both the type of donor and the solvent applied. Using a trichloroacetimidate donor in 1,4-dioxane, the open glycosylation reactions proceeded with high regioselectivity and in good yields. Conventional glycosylations, on the other hand, afforded the α-(1,2)- and α-(1,3)-linked rhamnobioside derivatives with slightly higher yields via three-step longer syntheses.

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41

Mohammad-Salim, Haydar A., and Hassan H. Abdallah. "Theoretical Study of the [4+2] Cycloaddition Reaction of Trifluoroethylene with Five-membered Chalcogens Heterocyclic Compounds." ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY 7, no. 2 (December 28, 2019): 69–77. http://dx.doi.org/10.14500/aro.10575.

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[4+2] cycloaddition reaction has enormous significant in organic chemistry synthesis reactions and yet remains unexplored for the synthesis of fluorine-containing compounds. A density functional theory study of the stereo- and regioselectivity of the [4+2] cycloaddition reaction of trifluoroethylene with furan, thiophene, and selenophene was carried out in the gas phase. The B3LYP functional is used throughout in combination with 6-31G(d) basis set. The analysis of stationary points and the energetic parameters indicates that the reaction mechanism is concerted and confirms that the exo-adducts are thermodynamically and kinetically more favored than endo-adducts. The calculated branching ratio indicates that the exo-adducts have the higher percent yield than endoadducts and the yield of endo-adducts is increased only slightly on proceeding from furan, through thiophene, and onto selenophene. The analysis of the frontier molecular highest occupied molecular orbital (MO) and lowest unoccupied MO orbitals indicates that the exo-adducts are more stable due to their higher energy gab. The reaction energies were compared to the MP2/6-31G(d) and CCSD(T)/6-31G(d) calculations.

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42

Shing, Tony K. M., Annie W. F. Wong, Taketo Ikeno, and Tohru Yamada. "Experimental and Theoretical Studies on Stereo- and Regioselectivity in Intramolecular Nitrone−Alkene Cycloaddition of Hept-6-enoses Derived from Carbohydrates." Journal of Organic Chemistry 71, no. 8 (April 2006): 3253–63. http://dx.doi.org/10.1021/jo060348y.

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43

Kanemasa, Shuji, Osamu Uchida, Eiji Wada, and Hidetoshi Yamamoto. "Unusual Stereo- and Regioselectivity Observed in Cycloadditions of theN-Titanated Azomethine Ylides Derived fromt-Butyl (Benzylideneamino)acetate with α,β-Unsaturated Esters." Chemistry Letters 19, no. 1 (January 1990): 105–8. http://dx.doi.org/10.1246/cl.1990.105.

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44

Timmins, Amy, and Sam P. de Visser. "A Comparative Review on the Catalytic Mechanism of Nonheme Iron Hydroxylases and Halogenases." Catalysts 8, no. 8 (July 31, 2018): 314. http://dx.doi.org/10.3390/catal8080314.

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Enzymatic halogenation and haloperoxidation are unusual processes in biology; however, a range of halogenases and haloperoxidases exist that are able to transfer an aliphatic or aromatic C–H bond into C–Cl/C–Br. Haloperoxidases utilize hydrogen peroxide, and in a reaction with halides (Cl−/Br−), they react to form hypohalides (OCl−/OBr−) that subsequently react with substrate by halide transfer. There are three types of haloperoxidases, namely the iron-heme, nonheme vanadium, and flavin-dependent haloperoxidases that are reviewed here. In addition, there are the nonheme iron halogenases that show structural and functional similarity to the nonheme iron hydroxylases and form an iron(IV)-oxo active species from a reaction of molecular oxygen with α-ketoglutarate on an iron(II) center. They subsequently transfer a halide (Cl−/Br−) to an aliphatic C–H bond. We review the mechanism and function of nonheme iron halogenases and hydroxylases and show recent computational modelling studies of our group on the hectochlorin biosynthesis enzyme and prolyl-4-hydroxylase as examples of nonheme iron halogenases and hydroxylases. These studies have established the catalytic mechanism of these enzymes and show the importance of substrate and oxidant positioning on the stereo-, chemo- and regioselectivity of the reaction that takes place.

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Bykov, V. I., T. A. Butenko, and E. Sh Finkel'shtein. "Stereo- and regioselectivity of the catalytic system MoCl5/SiO2-SnMe4 in the reaction of metathesis and cometathesis of olefins and their functional derivatives." Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 39, no. 1 (January 1990): 151–55. http://dx.doi.org/10.1007/bf00963021.

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Boutin, Rebecca, Samuel Koh, and William Tam. "Recent Advances in Transition Metal-Catalyzed Reactions of Oxabenzonorbornadiene." Current Organic Synthesis 16, no. 4 (July 4, 2019): 460–84. http://dx.doi.org/10.2174/1570179416666181122094643.

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Background: Oxabenzonorbornadiene (OBD) is a useful synthetic intermediate capable of undergoing multiple types of transformations due to three key structural features: a free alkene, a bridged oxygen atom, and a highly strained ring system. Most notably, ring-opening reactions of OBD using transition metal catalysts and nucleophiles produce multiple stereocenters in a single step. The resulting dihydronaphthalene framework is found in many natural products, which have been shown to be biologically active. Objective: This review will provide an overview of transition metal-catalyzed reactions from the past couple of years including cobalt, copper, iridium, nickel, palladium and rhodium- catalyzed reactions. In addition, the recent derivatization of OBD to cyclopropanated oxabenzonorbornadiene and its reactivity will be discussed. Conclusion: It can be seen from the review, that the work done on this topic has employed the use of many different transition metal catalysts, with many different nucleophiles, to perform various transformations on the OBD molecule. Additionally, depending on the catalyst and ligand used, the stereo and regioselectivity of the product can be controlled, with proposed mechanisms to support the understanding of such reactions. The use of palladium has also generated a cyclopropanated OBD, with reactivity similar to that of OBD. An additional reactive site exists at the distal cyclopropane carbon, giving rise to three types of ring-opened products.

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Maurer, Dirk, Thilak Reddy Enugala, Emil Hamnevik, Paul Bauer, Malin Lüking, Dušan Petrović, Heidi Hillier, Shina C. L. Kamerlin, Doreen Dobritzsch, and Mikael Widersten. "Stereo- and Regioselectivity in Catalyzed Transformation of a 1,2-Disubstituted Vicinal Diol and the Corresponding Diketone by Wild Type and Laboratory Evolved Alcohol Dehydrogenases." ACS Catalysis 8, no. 8 (July 5, 2018): 7526–38. http://dx.doi.org/10.1021/acscatal.8b01762.

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Závada, Jiří, Magdalena Pánková, and Antonín Vítek. "On the origin of base concentration effect on stereo- and regioselectivity in alkoxide-promoted E2 reactions: A consequence of substrate solvation by metal ions." Collection of Czechoslovak Chemical Communications 55, no. 3 (1990): 695–703. http://dx.doi.org/10.1135/cccc19900695.

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The title problem has been investigated in the reaction of 2-decyl bromide with t-C4H9OK/t-C4H9OH system employing 18-crown-6 ether and an "inert" salt (t-C4H9OLi) as mechanistic probes. From olefin-distribution data and a subsidiary kinetic evidence it has been inferred that the investigated effect originates from a concentration-dependent substrate solvation by metal ions in the transition state.

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Crotti, Paolo, Fabrizio Badalassi, Valeria Di Bussolo, Lucilla Favero, and Mauro Pineschi. "Corrigendum to “Stereo- and regioselectivity of cyclization reactions in conformationally restricted epoxy ketones: evaluation of C- versus O-alkylation process”[Tetrahedron 57 (2001) 8559–8557]." Tetrahedron 57, no. 52 (December 2001): 10395. http://dx.doi.org/10.1016/s0040-4020(01)01135-8.

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Black, Kersey A., and Pierre Vogel. "Regioselectivity of electrophilic additions to 7-oxabicyclo[2.2.1]heptenes controlled by remote substituents. Arenesulfonyl substituted 7-oxabicyclo[2.2.1]heptenes as stereo- and regioselective chiral dienophiles." Journal of Organic Chemistry 51, no. 26 (December 1986): 5341–48. http://dx.doi.org/10.1021/jo00376a054.

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