Synthesis and Reactivity of a Zinc Diazoalkyl Complex: 3+2 Cycloaddition Reaction with Carbon Monoxide

摘要

Abstract This work reports the synthesis, characterization, and reactivity of the first example of a well‐defined zinc α‐diazoalkyl complex. Treatment of zinc(I)‐zinc(I) bonded compound L2Zn2 L=CH3C(2,6‐iPr2C6H3N)CHC(CH3)(NCH2CH2PPh2) or zinc(II) hydride LZnH with trimethylsilyldiazomethane affords zinc diazoalkyl complex LZnC(N2)SiMe3. This complex liberates N2 in the presence of a nickel catalyst to form an α‐zincated phosphorus ylide by reacting with the pendant phosphine. It selectively undergoes formal 3+2 cycloaddition with CO2 or CO to form the corresponding product with a five‐membered heterocyclic core. Notably, the use of CO in such a 3+2 cycloaddition reaction is unprecedented, reflecting a novel CO reaction mode.