Cooperative, highly enantioselective phosphinothiourea catalysis of imine-allene [3+2] cycloadditions
Cooperative, highly enantioselective phosphinothiourea catalysis of imine-allene [3+2] cycloadditions
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DOI：
10.1021/ja801344w
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发表时间：
2008-04-30
影响因子：
15
通讯作者：
Jacobsen, Eric N.
中科院分区：
文献类型：
--
作者：
Fang, Yuan-Qing;Jacobsen, Eric N.
开发了一个新的膦硫脲催化剂系列，用于通过缺电子丙二烯与芳基和杂芳基二苯基膦酰亚胺的 [3 + 2] 环加成高度对映选择性合成 2-芳基-2,5-氢吡咯。人们发现，H(2)O 和 Et(3)N 作为添加剂的存在对于实现最佳速率非常重要。双功能催化剂对亲核试剂和亲电试剂的双重活化被用来解释观察到的高反应性和对映选择性。
A new family of phosphinthiourea catalysts was developed for the highly enantioselective synthesis of 2-aryl-2,5-hydropyrroles via a [3 + 2] cycloaddition of an electron-deficient allene with aryl and heteroaryl diphenylphosphinoylimines. The presence of both H(2)O and Et(3)N as additives was found to be important for achieving optimal rates. Dual activation of both nucleophile and electrophile by the bifunctional catalyst is invoked to account for the observed high reactivity and enantioselectivity.