γ‐, Diastereo‐, and Enantioselective Addition of MEMO‐Substituted Allylboron Compounds to Aldimines Catalyzed by Organoboron–Ammonium Complexes
作者:Ryan J. Morrison、Amir H. Hoveyda
DOI:10.1002/anie.201805811
日期:2018.9.3
addition step. Aryl‐, heteroaryl‐, alkenyl‐ and alkyl‐substituted vicinal phosphinoylamido MEM‐ethers were thus accessed in 57–92 % yield, 89:11 to >98:2 γ:α selectivity, 76:24–97:3 diastereomeric ratio, and 90:10–99:1 enantiomeric ratio. The method is scalable, and the phosphinoyl and MEM groups may be removed selectively or simultaneously. Utility is highlighted by enantioselective synthesis of an NK‐1
提出了第一种将O-取代的烯丙基B(pin)化合物添加到膦基嘧啶(MEM =甲氧基乙氧基甲基,pin = pinacolato)的催化,广泛适用,高效,γ-,非对映和对映选择性的方法。考虑到催化循环不同阶段的空间和电子要求,即手性烯丙基硼酸酯的产生,随后的1,3-硼酸根的形成,确定了最有效的催化剂和有机硼试剂的最佳保护基的身份。移位,以及加法步骤。因此,获得了芳基,杂芳基,烯基和烷基取代的邻位膦基酰胺基MEM醚,产率为57-92%,选择性为89:11至> 98:2γ:α,非对映体比率为76:24-97:3,和90:10–99:1对映体比率。该方法是可扩展的,膦酰基和MEM基团可选择性或同时除去。NK-1受体拮抗剂的对映选择性合成突出了实用性。