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The synthesis of a range of 3-pyrrolines has been achieved from primary ami
ne starting materials using a two-step alkylation/alkylldene carbene CH-Ins
ertion reaction sequence. We have shown that insertion into a range of CH-b
ond types is possible, and the formation of nitrogen-bearing quaternary ste
reocenters is a relatively facile process. The insertion reaction occurs wi
th > 95% retention of stereochemistry, but the presence of protecting group
s on nitrogen is generally deleterious to the cyclization process.