Synthesis of Enantiomerically Pure Allenes with Central and Axial Chirality Mediated by a Remote Sulfinyl Group
作者:José García Ruano、José Alemán、Vanesa Marcos
DOI:10.1055/s-0029-1217006
日期:2009.10
Enantiomerically pure 2-(p-tolylsulfinyl)benzylcopper reagents react with propargyl bromides and mesylates, affording enantiomerically pure allenes with central and axial chirality. Both regioselectivity (SN2′ processes) and configuration at the chiral axis are completely controlled by the sulfinyl group. The stereoselectivity at the benzylic position is very high. Complete kinetic resolution and moderate
对映体纯的2-(对甲苯基亚磺酰基)苄基铜试剂与炔丙基溴和甲磺酸酯反应,得到具有中心和轴向手性的对映体纯的烯。区域选择性(S N 2'过程)和在手性轴上的构型均完全由亚硫酰基控制。在苄基位置的立体选择性非常高。可以实现外消旋炔丙基甲磺酸酯的完全动力学拆分和中等动态拆分。可以通过假设亚砜基氧使苄基铜稳定并作为分子内S N 2'亲核进攻的前一步,将三键与金属缔合来解释这种立体化学行为。 丙二烯-亚磺酰基-轴向手性-中心手性-不对称合成