Control of product distribution in the domino metathesis reactions of N-alkynyl 2-azabicyclo[2.2.1]hept-5-en-3-ones. A convenient synthesis of functionalized γ-lactams and indolizidinones

In this report we describe the domino metathesis of N-alkynyl-2-aza-3-oxo-[2.2.1]hept-5-enes. The distribution of products of the domino processes of ROM–CM or ROM–RCM–CM depends on the starting material and on the catalyst used. A sequence of metathesis events has been proposed to account for these results. The procedure can be of use for the synthesis of lactams and indolizidinones.