α‐ and γ‐Regiocontrol and Enantiospecificity in the Copper‐Catalyzed Substitution Reaction of Propargylic Phosphates with Grignard Reagents
作者:Yuichi Kobayashi、Yuji Takashima、Yuuya Motoyama、Yukari Isogawa、Kyosuke Katagiri、Atsuki Tsuboi、Narihito Ogawa
DOI:10.1002/chem.202004413
日期:2021.2.19
s.) of the substitution reactions of secondary propargylic alcohol derivatives using reagents derived from ArMgBr and Cu salts were studied. First, the picolinate, 3‐methylpicolinate, and diethylphosphonate derivatives of Ph(CH2)2CH(OH)C≡CTMS were reacted with PhMgBr/CuCN in ratios of 2.5:2.7–2.5:0.25. The use of 2.5:0.25 ratio in THF/DME (6:1) at 0 °C for 1 h afforded the α‐substitution product from
研究了使用衍生自ArMgBr和Cu盐的试剂对仲炔丙醇衍生物进行取代反应的区域选择性(rs)和对映体特异性(es)。首先,使Ph(CH 2)2 CH(OH)C≡CTMS的吡啶甲酸,3-甲基吡啶甲酸和二乙基膦酸酯衍生物与PhMgBr / CuCN以2.5:2.7-2.5:0.25的比例反应。在0°C下于THF / DME(6:1)中使用2.5:0.25的比例1 h,可得到磷酸盐的α-取代产物,具有≥98%rs和99%es CuBr·Me 2 S,具有相似的选择性。然后将反应体系施加于从R衍生磷酸盐1 CH(OH)C≡CR 2和ArMgBr有R,以获得合成足够的RS和ES值2= TMS,Ph,而i Pr在大小上作为R 1取代基是临界的。取代基的在存在Ô的Ar位上轻微影响的选择性。我们还发现,在THF中以2:1的比例使用PhMgBr / Cu(acac)2会产生具有高rs和es的γ取代产物(丙二烯)