The Reaction of Chromium Alkenyl Carbene Complexes with Alkenyl Oxazolines: A Diastereoselective [3 + 2] Annulation Route to Cyclopentanones

All articles of this category Pentacarbonyl(alkenylmethoxy)carbene chromium complexes 1 undergo regio- and diastereoselective formal [3 + 2] cycloaddition to electron-deficient alkenes, e.g. alkenyl oxazoline derivatives 2 , affording cyclopentanoids 3 and 4 , the cis isomer 3 being the major stereoisomer. The cyclopropane intermediates 5 / 6 were isolated, under appropriate reaction conditions, and further converted into 3 and 4 . The cycloadduct 3b was efficiently elaborated into the 3,4-disubstituted cyclopentanones 10 and 11 . [3 + 2] annulation - carbene complexes - chromium - stereoselective synthesis - cyclopentanone - cycloadditions