1256484-41-9Relevant academic research and scientific papers
Chemo- and diastereoselective cyclopropanation of allylic amines and carbamates
Csatayová, Kristína,Davies, Stephen G.,Lee, James A.,Ling, Kenneth B.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.
, p. 8420 - 8440 (2010)
A highly chemo- and diastereoselective protocol for the cyclopropanation of tertiary allylic amines with Shi's carbenoid [CF3CO 2ZnCH2I] is described. The high levels of diastereoselectivity observed in these reactions may be attributed to chelation of the nitrogen atom to the zinc reagent, which then transfers a methylene unit to the syn-face of the olefin. Furthermore, a stereodivergent protocol for the cyclopropanation of a range of allylic carbamates has been developed, which provides access to both diastereoisomers of the corresponding cyclopropanes with very high levels of diastereoselectivity: cyclopropanation with the Wittig-Furukawa reagent [Zn(CH2I)2] proceeds under chelation control to give the corresponding syn-product, whilst reaction with Shi's carbenoid proceeds under steric control to give the corresponding anti-cyclopropane, in >95:5 dr in both cases.
