One-Pot Conversions of Olefins to Cyclic Carbonates and Secondary Allylic and Homoallylic Amines to Cyclic Carbamates
2010-11-19T00:00:00Z (GMT) by
Sequential treatment of a 1,2-disubstituted olefin with <i>m</i>-CPBA, Br<sub>3</sub>CCO<sub>2</sub>H, and DBU results in the one-pot, stereospecific conversion of the olefin to the corresponding disubstituted cyclic carbonate (1,3-dioxolan-2-one). The reaction proceeds via an initial epoxidation followed by S<sub>N</sub>2-type epoxide ring opening by Br<sub>3</sub>CCO<sub>2</sub>H and subsequent base-promoted carbonate formation upon elimination of bromoform. When a solution of a secondary allylic or homoallylic amine and Br<sub>3</sub>CCO<sub>2</sub>H is sequentially treated with <i>m</i>-CPBA then DBU, the product of the reaction is a cyclic carbamate (1,3-oxazolidin-2-one or 1,3-oxazinan-2-one).
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