AgNTf₂ catalyzed cycloaddition of N-acyliminium ions with alkynes for the synthesis of the 3,4-dihydro-1,3-oxazin-2-one skeleton

Abstract

A catalyzed process to 4,6-substituted 3,4-dihydro-1,3-oxazin-2-one skeleton has been developed through cycloaddition of in situ generated acyliminium intermediates with alkynes. A range of chain N,O-acetals and terminal alkynes were amenable...

In(OTf)3-catalyzed N-α phosphonylation of N,O-acetals with triethyl phosphite

“…Then, we extended this In(OTf) 3 -catalyzed N -α phosphonylation to benzyl activated N , O -acetals 9a–9j , 28 and the results are shown in Scheme 2. First, several 6- and 7-substituted 1,2,3,4-tetrahydroisoquinoline N , O -acetals 9a–9e were examined, and the desired products 10a–10e were obtained in excellent yields (82%–95%).…”