Enantioselective synthesis of α-halo-α-alkylmalonates via phase-transfer catalytic α-alkylation
作者:Suckchang Hong、Minsik Kim、Myunggi Jung、Min Woo Ha、Myungmo Lee、Yohan Park、Mi-hyun Kim、Taek-Soo Kim、Jihoon Lee、Hyeung-geun Park
DOI:10.1039/c3ob42107d
日期:——
A new enantioselective synthetic method for α-halo-α-alkylmalonates is reported. α-Alkylation of diphenylmethyl tert-butyl α-halomalonates under phase-transfer catalytic conditions (solid KOH, toluene, −40 °C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide (5 mol%) afforded diphenylmethyl tert-butyl α-halo-α-alkylmalonates in very high chemical yields (up to 99%) and optical yields (up
报道了α-卤代-α-烷基丙二酸酯的一种新的对映选择性合成方法。在(S,S)-3,4,5-三氟苯基-NAS溴化物存在下,在相转移催化条件下(固体KOH,甲苯,-40°C)α-卤代丙二酸二苯基甲基叔丁基酯的α-烷基化反应(5摩尔%)以非常高的化学收率(高达99%)和光学收率(高达93%ee)提供了α-卤代-α-烷基丙二酸二苯基甲基叔丁基酯。