Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
J Am Chem Soc. 2023 May 10;145(18):9976-9981. doi: 10.1021/jacs.3c01677. Epub 2023 Apr 26.
Chiral secondary organoboronic esters, when activated with -butyllithium, are shown to undergo efficient stereoretentive transmetalation with either zinc acetate or zinc chloride. This reaction provides chiral secondary alkylzinc reagents that are configurationally stable under practical experimental conditions. The organozinc compounds were found to engage in stereospecific reactions with difluorocarbene, catalytic cross-couplings with palladium-based catalysts, and trifluoromethylation with a copper(III) complex. Mechanistic and computational studies shed light on the inner workings of the transmetalation event.
手性仲有机硼酸酯与正丁基锂反应后，用乙酸锌或氯化锌进一步活化，可高效立体保留地与锌试剂发生转金属化反应。该反应提供了构型稳定的手性仲烷基锌试剂，在实际实验条件下稳定。所得到的有机锌试剂可与二氟卡宾发生立体专一性反应、与钯基催化剂发生催化交叉偶联反应、与三氟甲磺酸铜发生三氟甲基化反应。反应机理和计算研究揭示了转金属化反应的内在机制。
