Gold(I)-catalyzed enantioselective [3+2] and [3+3] cycloaddition reactions of propargyl acetals/ketals
作者:Cristina Navarro、Nathan D. Shapiro、Maurizio Bernasconi、Takahiro Horibe、F. Dean Toste
DOI:10.1016/j.tet.2015.04.109
日期:2015.9
propargyl acetals/ketals and aldehydes is reported, which proceeds via stepwise migration-fragmentation of acetals/ketals and cycloaddition of the in situ generated gold-carbenoid intermediate. Various functionalized 2,5-dihydrofurans were obtained in good yields and high enantioselectivities. Furthermore, an example of the first gold(I) catalyzed [3+3] cycloaddition of secondary propargyl ketals and nitrones
炔丙基缩醛/缩醛和醛的不对称金(I)催化的[3 + 2]环加成反应,通过逐步缩聚缩醛/缩酮迁移和原位生成的金-类金化合物中间体环加成反应而进行。以高收率和高对映选择性获得了各种官能化的2,5-二氢呋喃。此外,提出了一个例子,是第一个金(I)催化的炔丙基缩酮和硝酮的[3 + 3]环加成反应。