A mild synthetic protocol to access 2-ester pyrroles through Cu(OTf)2-catalysed carbene insertion/ester migration/cyclization of enaminones and α-diazo compounds is reported.
Ambivalent role of metal chlorides in ring opening reactions of 2H-azirines: synthesis of imidazoles, pyrroles and pyrrolinones
作者:Sergio Auricchio、Ada M. Truscello、Mirvana Lauria、Stefano V. Meille
DOI:10.1016/j.tet.2012.06.069
日期:2012.9
the presence of metal salts. Imidazoles, pyrroles and new pyrrolinones derivatives are isolated in good overall yields. The role of metal salts was investigated as they can act as Lewis acids or electron donors. Mechanisms are proposed suggesting that imidazoles arise from addition of azirine to imines via radical or ionic mechanism; pyrroles and pyrrolinones are obtained from azirines with enamino
Facile Regiocontrolled Three-Step Synthesis of Poly-Substituted Furans, Pyrroles, and Thiophenes: Consecutive Michael Addition of Methyl Cyanoacetate to α,β-Enone, CuI-Mediated Aerobic Oxidation, and Acid-Catalyzed Paal-Knorr Synthesis
作者:Se-Hee Kim、Jin-Woo Lim、Cheol-Hee Lim、Jae-Nyoung Kim
DOI:10.5012/bkcs.2012.33.2.620
日期:2012.2.20
December 19, 2011An efficient synthesis of poly-substituted furans, pyrroles, and thiophenes was carried out in a regiocontrolledmanner via a three-step process; (i) conjugate addition of methyl cyanoacetate derivatives to α,β-enones, (ii)CuI-mediated aerobic oxidation, and (iii) Paal-Knorr type synthesis of five-membered heterocycles. Key Words : Furans, Pyrroles, Thiophenes, CuI, Paal-Knorr synthesisIntroductionRecently
E-mail: kimjn@chonnam.ac.kr 2011年12月6日接收,2011年12月19日接受 (i) 氰基乙酸甲酯衍生物与 α,β-烯酮的共轭加成,(ii) CuI 介导的有氧氧化,和 (iii) 五元杂环的 Paal-Knorr 型合成。关键词:呋喃,吡咯,噻吩,CuI,Paal-Knorr 合成介绍最近,我们报道了通过氰基乙酸甲酯与α,β-不饱和酮的共轭加成和随后的 CuI 介导的需氧氧化合成 2,5-二酮酯的有效方法。
Solvent-Free Thermal and Microwave-Assisted [3 + 2] Cycloadditions between Stabilized Azomethine Ylides and Nitrostyrenes. An Experimental and Theoretical Study
作者:Ana Arrieta、Dorleta Otaegui、Aizpea Zubia、Fernando P. Cossío、Angel Díaz-Ortiz、Antonio de la Hoz、M. Antonia Herrero、Pilar Prieto、Concepción Foces-Foces、José L. Pizarro、María I. Arriortua
DOI:10.1021/jo062672z
日期:2007.6.1
[3 + 2] cycloadditionbetween stabilized azomethine ylides and nitrostyrenes have been analyzed using experimental and computational approaches. It has been observed that, in the absence of solvent, three stereoisomers are formed, both under classical heating conditions and under microwave irradiation. This result contrasts with that observed in solution under classical thermal conditions. The 4-nitropyrrolidines