Lewis acid catalysis of photochemical reactions. 8. Photodimerization and cross-cycloaddition of coumarin
作者:Frederick D. Lewis、Steven V. Barancyk
DOI:10.1021/ja00205a015
日期:1989.11
Photodimerisation de la coumarine en hexahydro-6,6a,6b,7,12b,12c cyclobuta [1,2-c:4,3-c']-et-[1,2-c:3,4-c'] bisbenzopyranne-1 diones-6,7 et -6,12
香豆素六氢-6,6a,6b,7,12b,12c cyclobuta [1,2-c:4,3-c']-et-[1,2-c:3,4-c'] 的光二聚化双苯并吡喃-1 diones-6,7 et -6,12
Catalytic asymmetric conjugate addition of Grignard reagents to coumarins—synthesis of versatile chiral building blocks
作者:Johannes F. Teichert、Ben L. Feringa
DOI:10.1039/c0cc05160h
日期:——
A new protocol for the Cu-catalysed asymmetric conjugate addition of Grignardreagents to coumarins has been developed. The corresponding products are formed in high yields and enantioselectivities. Through a sequential protocol involving conjugate addition followed by nucleophilic ring opening of the chiral enolate, chiral esters and amides are readily accessible.
Chiral ferrocene phosphane-carbenes are good ligands for the copper-catalyzed 1,4-addition of Grignard reagents to various Michael acceptors. The products were obtained in high enantiomeric purity (up to e.r. = 95:5) and excellent regioselectivity (r.r. = 99:1). These ligands are also useful for domino conjugate addition followed by enolate trapping with imine and aldehyde. (C) 2013 Elsevier B.V. All rights reserved.
Patra, Amarendra; Misra, Swapan K., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1988, vol. 27, # 1-12, p. 272 - 273