Academic literature on the topic '3-substituted pyrroles'

Huanfeng Jiang of the South China University of Technology showed (J. Org. Chem. 2010, 75, 966) that an alkynoate 1 could be condensed with a 1,3-dicarbonyl compound 2 to give, under oxidizing conditions, the furan 3. Phil Ho Lee of Kangwon National University found (Tetrahedron Lett. 2010, 51, 1899) that the enyne 4 cyclized smoothly to the furan 5. Yahong Li of Suzhou University and Vladimir Gevorgyan of the University of Illinois, Chicago, demonstrated (J. Am. Chem. Soc. 2010, 132, 7645) that the cyclization of 6 proceeded with silyl migration, to give 7. François Bilodeau and Pat Forgione of Boehringer Ingelheim (Canada) optimized (J. Org. Chem. 2010, 75, 1550) the Pd-mediated decarboxylative coupling of a furoic acid 8 with 9 to give 10. This protocol also worked well with pyrrole carboxylic acids. In another transformation of a preformed pyrrole, Masatomo Iwao of Nagasaki University observed (Organic Lett. 2010, 12, 2734) that in the presence of LDA/diisopropylamine, the initially formed 2-anion from the deprotonation of 11 gave the 2-product 12 with more reactive electrophiles but the 5-product 13 with less reactive electrophiles. Umasish Jana of Jadavpur University developed (J. Org. Chem. 2010, 75, 1674) a route to more highly substituted pyrroles such as 17 using the remarkable four-component coupling of 14, 15, and 16 with nitromethane, the carbon of which was incorporated in the product. Laura L. Anderson, also of the University of Illinois, Chicago, designed (Organic Lett. 2010, 12, 2290) a clever approach to pyrroles, based on the Ir-catalyzed rearrangement of O-allyl oximes such as 18. Xiaofeng Tong of the East China University of Science and Technology reported (Chem. Commun. 2010, 312) the condensation of 20 with 21 to give the dihydropyridine 22. Base-mediated elimination of sulfinate could convert 22 into the pyridine. Jin-Quan Yu of Scripps/La Jolla found (Angew. Chem. Int. Ed. 2010, 49, 1275) that Pd-mediated activation of the nictotinamide 23 proceeded with high regioselectivity, leading to 25. Zhiping Li of Remnin University of China demonstrated (J. Org. Chem. 2010, 75, 4636) that the chloroenamine 26 cyclized to the indole 27 on exposure to NaI.

Yasutaka Ishii of Kansai University has developed (J. Org. Chem. 2007, 72, 8820) a novel route to furans, using a mixed-metal catalyst to effect condensation of an aldehyde or 1,3 diketone such as 1 with an acceptor such as 2 to give the 3-furoate 3. In a complementary approach, Yong-Min Liang of Lanzhou University has found (J. Org. Chem. 2007, 72, 10276) that diazoacetate 5 will condense with an alkynyl ketone to give the 2-furoate 6. David W. Knight of Cardiff University has shown (Tetrahedron Lett. 2007, 48, 7709) that an alkynyl diol such as 7, readily available by dihydroxylation of the corrresponding alkenyl alkyne, cyclized to the furan on exposure to AgNO3 on silica gel. Professor Knight has also (Tetrahedron Lett. 2007, 48, 7906) established a route to poly-substituted pyrroles 10, by iodination of alkynyl sulfonamides such as 9. Similarly, Richard C. Larock of Iowa State University found (J. Org. Chem. 2007, 72, 9643) that I-Cl cyclized methoximes such as 11 to the corresponding iodo isoxazole 12, and Stephen L. Buchwald of MIT uncovered (Organic Lett. 2007, 9, 5521) the cyclization of an enamide such as 13 with I2 to the corresponding oxazole 14. In developing a more efficient route to a new class of materials that he has named “triazolamers”, Paramjit S. Arora of New York University was able (J. Org. Chem. 2007, 72, 7963) to effect diazo transfer to the amine 15 and subsequent condensation with 16 to give 17, without isolation of the intermediate azide. C. V. Asokan and E. R. Anabha of Mahatma Gandhi University have described (Tetrahedron Lett. 2007, 48, 5641) the activation of a ketone 18 followed by condensation with malononitrile 19 to give the pyridine 20. Hans-Ulrich Reissig of the Freie Universität Berlin has established (Organic Lett. 2007, 9, 5541) a complementary three-component coupling of a nitrile 21 with the allenyl anion 22, followed by a carboxylic acid 23 to deliver the pyridine 24. Akio Saito and Yuji Hanzawa of the Showa Pharmaceutical University have reported (Tetrahedron Lett. 2007, 48, 6852) the intramolecular Rh-catalyzed cyclization of a methoxime lactone such as 25 to the pyridine 26.

Kyungsoo Oh of Chung-Ang University cyclized (Org. Lett. 2015, 17, 450) the chloro enone 1 with NBS to the furan 2. Hongwei Zhou of Zhejiang University acylated (Adv. Synth. Catal. 2015, 357, 389) the imine 3, leading to the furan 4. H. Surya Prakash Rao of Pondicherry University found (Synlett 2014, 26, 1059) that under Blaise conditions, exposure of 5 to three equivalents of 6 led to the pyrrole 7. Yoshiaki Nishibayashi of the University of Tokyo and Yoshihiro Miyake, now at Nagoya University, prepared (Chem. Commun. 2014, 50, 8900) the pyrrole 10 by adding the silane 9 to the enone 8. Barry M. Trost of Stanford University developed (Org. Lett. 2015, 17, 1433) the phosphine-mediated cyclization of 11 to an intermediate that on brief exposure to a Pd catalyst was converted to the pyridine 12. Nagatoshi Nishiwaki of the Kochi University of Technology added (Chem. Lett. 2015, 44, 776) the dinitrolactam 14 to the enone 13 to give the pyridine 15. Metin Balci of the Middle East Technical University assembled (Org. Lett. 2015, 17, 964) the tricyclic pyridine 18 by adding propargyl amine 17 to the aldehyde 16. Chada Raji Reddy of the Indian Institute of Chemical Technology cyclized (Org. Lett. 2015, 17, 896) the azido enyne 19 to the pyridine 20 by simple exposure to I2. Björn C. G. Söderberg of West Virginia University used (J. Org. Chem. 2015, 80, 4783) a Pd catalyst to simultaneously reduce and cyclize 21 to the indole 22. Ranjan Jana of the Indian Institute of Chemical Biology effected (Org. Lett. 2015, 17, 672) sequential ortho C–H activation and cyclization, adding 23 to 24 to give the 2-substituted indole 25. In a complementary approach, Debabrata Maiti of the Indian Institute of Technology Bombay added (Chem. Eur. J. 2015, 21, 8723) 27 to 26 to give the 3-substituted indole 28. In a Type 8 construction, Nobutaka Fujii and Hiroaki Ohno of Kyoto University employed (Chem. Eur. J. 2015, 21, 1463) a gold catalyst to add 30 to 29, leading to 31.

Nabyl Merbouh and Robert Britton of Simon Fraser University developed (Eur. J. Org. Chem. 2013, 3219) a general route to a 2,5-disubstituted furan 3 by taking advantage of the ready α-chlorination of an aldehyde 1, followed by coupling with a ketone eno­late 2. Jérôme Waser of the Ecole Polytechnique Fédérale de Lausanne used (Angew. Chem. Int. Ed. 2013, 52, 6743) 5 to oxidize the allene 4 to the furan 6. Qian Zhang and Xihe Bi of Northeast Normal University used (Angew. Chem. Int. Ed. 2013, 52, 6953) Ag catalysis to prepare the pyrrole 9 by coupling the alkyne 7 with the isonitrile 8. Aiwen Lei of Wuhan University reported (Angew. Chem. Int. Ed. 2013, 52, 6958) similar results. Professor Lei also developed (Chem. Commun. 2013, 49, 5853) the Pd-catalyzed oxidation of the allyl imine 10 to the pyrrole 11. Kamal K. Kapoor of the University of Jammu reduced (Tetrahedron Lett. 2013, 54, 5699) the Michael adduct 12 to the pyrrole 13 with triethyl phosphite. Edgar Haak of the Otto-von-Guericke-Universität, Magdeburg condensed (Eur. J. Org. Chem. 2013, 7354) the alkynyl carbinol 14 with aniline to give the N-phenyl pyrrole 15. Jean Rodriguez and Thierry Constantieux of Aix-Marseille Université prepared (Eur. J. Org. Chem. 2013, 4131) the pyridine 18 by combining the ketone 16 and the unsaturated aldehyde 17 with NH4OAc. Teck-Peng Loh of the University of Sciences and Technology of China and Nanyang Technological University found (Angew. Chem. Int. Ed. 2013, 52, 8584) that TMEDA was an effective organocatalyst for the assembly of the pyridine 21 from 19 and 20. Andrew D. Smith of the University of St Andrews showed (Angew. Chem. Int. Ed. 2013, 52, 11642) that the pyridyl tosylate 24, avail­able by the combination of 22 and 23, readily coupled with both carbon and amine nucleophiles. In a related development, D. Tyler McQuade of Florida State University prepared (Org. Lett. 2013, 15, 5298) the 2-bromopyridine 26 from the alkylidene malononitrile 25. Two versatile approaches to substituted indoles were recently described. David F. Wiemer of the University of Iowa cyclized (J. Org. Chem. 2013, 78, 9291) the Stobbe product 27 to the 3-bromo indole 28.

Rubén Vicente and Luis A. López at the University of Oviedo in Spain reported (Angew. Chem. Int. Ed. 2012, 51, 8063) the synthesis of cyclopropyl furan 2 from alkylidene 1 and styrene by way of a zinc carbene intermediate. The same substrate 1 was also converted (Angew. Chem. Int. Ed. 2012, 51, 12128) to furan 3 via catalysis with tetrahydrothiophene in the presence of benzoic acid by J. Stephen Clark at the University of Glasgow. Xue-Long Hou at the Shanghai Institute of Organic Chemistry discovered (Org. Lett. 2012, 14, 5756) that palladacycle 6 catalyzes the conversion of bicyclic alkene 4 and alkynone 5 to furan 7. A silver-mediated C–H/C–H functionalization strategy for the synthesis of furan 9 from alkyne 8 and ethyl acetoacetate was developed (J. Am. Chem. Soc. 2012, 134, 5766) by Aiwen Lei at Wuhan University. Ning Jiao at Peking University and East China Normal University found (Org. Lett. 2012, 14, 4926) that azide 10 and aldehyde 11 could be converted to either pyrrole 12 or 13 with complete regiocontrol by judicious choice of a metal catalyst. Meanwhile, Michael A. Kerr at the University of Western Ontario developed (Angew. Chem. Int. Ed. 2012, 51, 11088) a multicomponent synthesis of pyrrole 16 involving the merger of nitrone 14 and the donor–acceptor cyclopropane 15. The pyrrole 16 was subsequently converted to an intermediate in the synthesis of the cholesterol-lowering drug compound Lipitor. A robust synthesis of the ynone trifluoroboronate 17 was developed (Org. Lett. 2012, 14, 5354) by James D. Kirkham and Joseph P.A. Harrity at the University of Sheffield, which thus allowed for the ready production of trifluoroboronate-substituted pyrazole 18. An alternative pyrazole synthesis via oxidative closure of unsaturated hydrazine 19 to produce 20 was reported (Org. Lett. 2012, 14, 5030) by Yu Rao at Tsinghua University. A unique fluoropyrazole construction was developed (Angew. Chem. Int. Ed. 2012, 51, 12059) by Junji Ichikawa at the University of Tsukuba that involved nucleophilic substitution of two of the fluorides in 21 to form pyrazole 22.

Xin-Yan Wu of East China University of Science and Technology and Jun Yang of the Shanghai Institute of Organic Chemistry added (Tetrahedron Lett. 2014, 55, 4071) the Grignard reagent 1 to propargyl alcohol 2 to give an intermediate that could be bory­lated, then coupled under Pd catalysis with an anhydride, leading to the furan 3. Fuwei Li of the Lanzhou Institute of Chemical Physics constructed (Org. Lett. 2014, 16, 5992) the furan 6 by oxidizing the keto ester 4 in the presence of the enamide 5. Yuanhong Liu of the Shanghai Institute of Organic Chemistry prepared (Angew. Chem. Int. Ed. 2014, 53, 11596) the pyrrole 9 by reducing the azadiene 7 with the Negishi reagent, then adding the nitrile 8. Yefeng Tang of Tsinghua University found (Tetrahedron Lett. 2014, 55, 6455) that the Rh carbene derived from 11 could be added to an enol silyl ether 10 to give the pyrrole 12. Pazhamalai Anbarasan of the Indian Institute of Technology Madras reported (J. Org. Chem. 2014, 79, 8428) related results. Zheng Huang of the Shanghai Institute of Organic Chemistry established (Angew. Chem. Int. Ed. 2014, 53, 1390) a connection between substituted piperidines and pyridines by dehydrogenating 13 to 15, with 14 as the acceptor. Joseph P. A. Harrity of the University of Sheffield conceived (Chem. Eur. J. 2014, 20, 12889) the cascade assembly of the pyridine 18 by cycloaddition of 16 with 17 followed by Pd-catalyzed coupling. Teck-Peng Loh of Nanyang Technological University converted (Org. Lett. 2014, 16, 3432) the keto ester 19 into the azirine, then eliminated it to form an aza­triene that cyclized to the pyridine 20. En route to a cholesteryl ester transfer protein inhibitor, Zhengxu S. Han of Boehringer Ingelheim combined (Org. Lett. 2014, 16, 4142) 21 with 22 to give an intermediate that could be oxidized to 23. Magnus Rueping of RWTH Aachen used (Angew. Chem. Int. Ed. 2014, 53, 13264) an Ir photoredox catalyst in conjunction with a Pd catalyst to cyclize the enamine 24 to the indole 25. Yingming Yao and Yingsheng Zhao of Soochow University effected (Angew. Chem. Int. Ed. 2014, 53, 9884) oxidative cyclization of 26 to 27.

Ryoichi Kuwano of Kyushu University showed (J. Am. Chem. Soc. 2008, 130, 808) that diastereomerically and enantiomerically pure pyrollidines such as 2 could be prepared by hydrogenation of the corresponding pyrrole. Victor S. Martín of Universidad de la Laguna found (Organic Lett. 2008, 10, 2349) that the stereochemical outcome of the pyrrolidine-forming Nicholas cyclization could be directed by the protecting group on the N. Jianbo Wang of Peking University established (J. Org. Chem. 2008, 73, 1971) a convenient route to diazo esters such as 6. N-H insertion led to the pyrrolidine, which Zhen-Jiang Xu of the Shanghai Institute of Organic Chemistry and Chi-Ming Che of the University of Hong Kong showed (Organic Lett. 2008, 10, 1529) could be reduced with high diastereoselectivity to the hydroxy ester 7. Alternatively, Professor Wang found that photochemical Wolff rearrangement of 6 delivered the pyrrolidone 8 . Martin J. Slater and Shiping Xie of GlaxoSmithKline optimized (J. Org. Chem. 2008, 73, 3094) the hydroquinine catalyzed enantioselective 3+2 cycloaddition of 9 and 10, leading to the pyrrolidine 11 with high diastereocontrol. Shu Kobayashi of the University of Tokyo developed (Adv. Synth. Cat. 2008, 350, 647) a practical protocol for the aza Diels-Alder construction of enantiomerically-pure piperidines such as 14 . Biao Yu of the Shanghai Institute of Organic Chemistry cyclized (Tetrahedron Lett. 2008, 49, 672) the product from the proline-catalyzed enantioselective aldol of 15 and 16, leading to the substituted piperidine 17 . Michael Shipman of the University of Warwick described (Tetrahedron Lett. 2008, 49, 250) the cyclization of the aziridine derived from 18, that proceeded to give 19 as a single diastereomer, apparently via kinetic side-chain protonation. Takeo Kawabata of Kyoto University found (J. Am. Chem. Soc. 2008, 130, 4153) that intramolecular alkylation to form four, five and six-membered rings from amino esters such as 21 proceeded with remarkable enantioretention. Géraldine Masson and Jieping Zhu of CNRS, Gif-sur-Yvette, condensed (Organic Lett. 2008, 10, 1509) cinnamaldehyde 23 with cyanide and an ω-alkenyl amine to give the intramolecular aza-Diels-Alder substrate 24. Hongbin Zhai of the Shanghai Institute of Organic Chemistry acylated (J. Org. Chem. 2008, 73, 3589) 26 with 27, leading to the ring-closing metathesis precursor 28.