The stereochemistry of organometallic compounds. XXXVI. Rhodium-catalysed reactions of unsaturated amines with hydrogen and carbon monoxide. A new synthesis of 2-piperidinones

Rhodium-catalysed reactions of 5-aminopent-1-enes with carbon monoxide and hydrogen give 2-piperidinone derivatives in high yields under mild conditions. Reaction of allylamine under similar conditions gave exclusively 2-pyrrolidone in high yield and reactions of 4-aminobut-1-enes gave mixtures of 2-piperidinones and 2-pyrrolidinones. The role of the hydrogen in these reactions is discussed.