Singlet oxygenation of 1-aminomethyl-1-tert-butyl-2-methoxy-2-(3-methoxyphenyl)ethylenes: Marked effect of allylic nitrogen on the reaction pathways and chemoselectivity

Article abstract of DOI:10.1016/0040-4039(96)01858-8

The character of an allylic nitrogen affects significantly the reaction pathways as well as the chemoselectivity in the singlet oxygenation of allylic amines (1, 5, 7 and 11). Secondary amines (1a, b) undergo α-oxidation to give imines (2). A primary amine (1c) and amides (7a-c) undergo preferentially the 1,2-addition of singlet oxygen, whereas the singlet oxygenation of an amide (5) afforded selectively an 'ene' reaction product. For a lactum (11), the 1,2-addition and the 'ene' reaction of singlet oxygen occur concurrently.