Under photoirradiation conditions using xenon light, In the presence of a catalytic amount of PdCl2(PPh3)(2) with triethylamine as a base, a three-component coupling reaction of iodoalkanes, carbon monoxide, and terminal alkynes proceeded to give alkyl alkynyl ketones in good yields.
Asymmetric Synthesis of Fluorinated Allenes by Rhodium‐Catalyzed Enantioselective Alkylation/Defluorination of Propargyl Difluorides with Alkylzincs
作者:Jia Sheng Ng、Tamio Hayashi
DOI:10.1002/anie.202109290
日期:2021.9.13
The reaction of propargyl difluorides R1CF2C≡CR2 with alkylzincs R3ZnCl giving axially chiral fluorinated allenes R1FC=C=CR2R3 with high enantioselectivity (up to 99 % ee) was found to be catalyzed by a chiral diene/rhodium complex. A key step in the catalytic cycle is selective elimination of one of the enantiotopic fluorides at the β-position of an alkenyl-Rh intermediate, which is generated by regioselective
发现炔丙基二氟化物 R 1 CF 2 C≡CR 2与烷基锌 R 3 ZnCl 的反应得到具有高对映选择性(高达 99 % ee)的轴向手性氟化丙二烯 R 1 FC=C=CR 2 R 3手性二烯/铑配合物。催化循环中的一个关键步骤是选择性消除烯基-Rh 中间体 β 位的一种对映氟化物,它是通过将 R 3 -Rh区域选择性加成到起始二氟化物的三键上而产生的。