Reductive Cyclopropanations Catalyzed by Dinuclear Nickel Complexes
作者:You-Yun Zhou、Christopher Uyeda
DOI:10.1002/anie.201511271
日期:2016.2.24
Dinuclear Ni complexes supported by naphthyridine‐diimine (NDI) ligands catalyze the reductive cyclopropanation of alkenes with CH2Cl2 as the methylene source. The use of mild terminal reductants (Zn or Et2Zn) confers significant functional‐group tolerance, and the catalyst accommodates structurally and electronically diverse alkenes. Mononickel catalysts bearing related N chelates afford comparatively
Catalytic Asymmetric Cyclopropanations with Nonstabilized Carbenes
作者:Kristen E. Berger、Raymond J. Martinez、Jianhan Zhou、Christopher Uyeda
DOI:10.1021/jacs.3c01949
日期:2023.5.3
general methods for the synthesis of chiral cyclopropanes are catalytic additions of diazoalkanes to alkenes. However, a limitation of this approach is that diazoalkanes can only be safely handled on preparative scales if they possess stabilizing substituents. Here we show that gem-dichloroalkanes can serve as precursors to nonstabilized carbenes for asymmetriccyclopropanation reactions of alkenes.
Substrate-controlled C–H or C–C alkynylation of cyclopropanes: generation of aryl radical cations by direct light activation of hypervalent iodine reagents
作者:Tin V. T. Nguyen、Matthew D. Wodrich、Jerome Waser
DOI:10.1039/d2sc04344k
日期:——
arylcyclopropanes. Irradiation of ethynylbenziodoxolone (EBX) reagents with visible light at 440 nm promoted the reaction. By the choice of the aryl group on the cyclopropane, it was possible to completely switch the outcome of the reaction from the alkynylation of the C–H bond to the oxyalkynylation of the C–Cbond, which proceeded without the need for a catalyst, in contrast to previous works. The oxyalkynylation