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
Diazirinylidene (c-CN2) is formally the simplest of the N-heterocyclic carbenes. The intermediacy of this elusive species in the fragmentation of butyl 3-bromodiazirine-3-carboxylate (1a) with pent-4-en-1-ols and their sodium alkoxides in DMF is supported by the formation of 2-oxabicyclo[4.1.0]heptanes and dipentenoxymethanes. These products result from an intramolecular [2 + 1] cycloaddition and O–H