Conjugate Addition Reactions of Functionalized Organozinc and Copper Reagents to (2-Propynylidene)morpholinium Triflates
作者:Martina Brunner、Gerhard Maas
DOI:10.1055/s-1995-4024
日期:1995.8
Organozinc and copper reagents of the type IZnCu(CN)-RC-FG [RC-FG = cyanoalkyl (6a, c), ethoxycarbonylalkyl (6b, d), functionalized aryl (10a-c)] undergo conjugate addition to the (2-propynylidene)morpholinium triflates 1a, b. The expected morpholinoallenes or the tautomeric 1- or 2-morpholino-1,3-dienes cannot be isolated, however. After hydrolytic workup, α,β-unsaturated ketones 7 or 12 are usually obtained. In some cases, 2-acylcyclopent-2-en-1-ones 8 or 2-acylindenones 13 are found, which result from cyclization of the initially formed morpholinoallenes. The 2-morpholino-1,3-dienes 17 can be intercepted in a [4+2] cycloaddition with electron-deficient alkenes, and the cyclohexanones 19 are obtained after hydrolytic workup.
IZnCu(CN)-RC-FG [RC-FG = 氰烷基(6a, c),乙氧羰基烷基(6b, d),官能化芳基(10a-c)] 型有机锌和铜试剂与 (2-propynylidene)morpholinium triflates 1a, b 发生共轭加成反应,但不能分离出预期的吗啉烯或同分异构体 1-或 2-吗啉-1,3-二烯。经过水解处理后,通常会得到δ,δ-不饱和酮 7 或 12。在某些情况下,会发现 2-酰基环戊-2-烯-1-酮 8 或 2-酰基茚酮 13,它们是最初形成的吗啉烯环化的结果。2-吗啉基-1,3-二烯 17 可以在与缺电子烯的[4+2]环化反应中截获,而环己酮 19 则可以在水解加工后得到。