Experimental and Computational Studies for the Synthesis of Functionalized Cyclopropanes from 2-Substituted Allylic Derivatives with Ethyl Diazoacetate

Chemistry. 2024 Feb 7;30(8):e202303070. doi: 10.1002/chem.202303070. Epub 2023 Dec 18.

Abstract

The catalytic asymmetric synthesis of highly functionalized cyclopropanes from 2-substituted allylic derivatives is reported. Using ethyl diazo acetate, the reaction, catalyzed by a chiral ruthenium complex (Ru(II)-Pheox), furnished the corresponding easily separable cis and trans cyclopropanes in moderate to high yields (32-97 %) and excellent ee (86-99 %). This approach significantly extends the portfolio of accessible enantioenriched cyclopropanes from an underexplored class of olefins. DFT calculations suggest that an outer-sphere mechanism is operative in this system.

Keywords: asymmetric synthesis; computational studies; cyclopropane; diazo reagent; ruthenium catalyst.