The Effect of the Carbon Ligand on the Reaction of Organozinc Reagents in the Synthesis of Substituted 2,5-Dihydrofurans: A Rare Example of An Uncatalysed Allylic-Substitution Reaction Involving Alkyl Zinc Halides
作者:Mark Woods、Nuno Monteiro、Geneviève Balme
DOI:10.1002/(sici)1099-0690(200005)2000:9<1711::aid-ejoc1711>3.0.co;2-1
日期:2000.5
Organozinc halides derived from Grignard reagents behave differently in their reaction with ethyl (±±)-(2RS,3SR)-tetrahydro-4-methylene-2-phenyl-3-(phenylsulfonyl)furan-3-carboxylate (3) according to the hybridisation of the carbon ligand. During the development of short multi-component reactions for the synthesis of diverse functionalized ethyl 2,5-dihydrofuran-3-carboxylates it was discovered that
格氏试剂衍生的有机锌卤化物在与 (±±)-(2RS,3SR)-四氢-4-亚甲基-2-苯基-3-(苯磺酰基)呋喃-3-羧酸乙酯 (3) 的反应中表现不同碳配体的杂交。在开发用于合成多种官能化 2,5-二氢呋喃-3-羧酸乙酯的短多组分反应过程中,发现芳基和乙烯基卤化锌在 Pd(PPh3)4 存在下与 3 发生完全反应。相反,当烷基卤化锌在 Pd(PPh3)4 存在下与 3 反应时,观察到 3 的还原脱磺化。值得注意的是,在没有过渡金属催化剂的情况下,用烷基卤化锌对 3 的烯丙基取代进行得非常干净且产率适中。