Gandolfo Eugenio, Tang Xinjun, Raha Roy Sudipta, Melchiorre Paolo
ICIQ - Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avenida Països Catalans, 16-43007, Tarragona, Spain.
ICREA, Passeig Lluís Companys 23, 08010, Barcelona, Spain.
Angew Chem Int Ed Engl. 2019 Nov 18;58(47):16854-16858. doi: 10.1002/anie.201910168. Epub 2019 Oct 7.
Photochemical enantioselective nickel-catalyzed cross-coupling reactions are difficult to implement. We report a visible-light-mediated strategy that successfully couples symmetrical anhydrides and 4-alkyl dihydropyridines (DHPs) to afford enantioenriched α-substituted ketones under mild conditions. The chemistry does not require exogenous photocatalysts. It is triggered by the direct excitation of DHPs, which act as a radical source and as a reductant, facilitating the turnover of the chiral catalytic nickel complex.
光化学对映选择性镍催化交叉偶联反应难以实现。我们报道了一种可见光介导的策略，该策略能在温和条件下成功地将对称酸酐与4-烷基二氢吡啶（DHP）偶联，以得到对映体富集的α-取代酮。该化学过程不需要外源光催化剂。它由DHP的直接激发引发，DHP作为自由基源和还原剂，促进手性催化镍配合物的周转。
