Reactivity of mixed organozinc and mixed organocopper reagents: 12 . Three component reaction of mixed (n-alkyl)(diaryl)zincates, chloroformates and phosphines for the synthesis of esters
作者:Duygu Özkan、Ender Erdik
DOI:10.1016/j.jorganchem.2015.08.012
日期:2015.12
The reaction of mixed n-butyldiphenylzincate, n-BuPh2ZnMgBr with ethyl chloroformate, ClCOOEt in the presence n-Bu3P in THF takes place with quantitative yield and phenyl group transfer to give PhCOOEt. Ethoxycarbonylation of n-BuPh2ZnMgBr is preferable to the reaction of PhMgBr forming ester and triphenylcarbinol and also to the reaction of triphenylzincate, Ph3ZnMgBr for atom economy. Group selectivity
混合正butyldiphenylzincate,所述的反应Ñ -BuPh 2 ZnMgBr与氯甲酸乙酯在存在,ClCOOEt Ñ -Bu 3 p在THF发生以定量收率和苯基的基团转移给PhCOOEt。为了使原子经济,n- BuPh 2 ZnMgBr的乙氧基羰基化优选于PhMgBr形成酯与三苯基甲醇的反应,并且也优于三苯基锌酸酯Ph 3 ZnMgBr的反应。在膦基团选择性催化C-COOR的耦合Ñ -BuPh 2 ZnMgBr和Ñ -Bu 2 PhZnMgBr可以通过改变反应参数来控制。ñ-Bu 3 P催化的反应Ñ -BuPh 2 ZnMgBr与ClCOOEt发生与苯基选择性而反应Ñ -Bu 2与ClCOOPh结果PhZnMgBr在Ñ丁基传输。在两种锌酸盐的乙氧基羰基化反应中,Ph 3 P的催化作用均会增加正丁基:苯基的转移率。正丁基(芳基)2 ZnMgBr试剂与ClCOOEt在THF中的n-