DABCO-mediated [3+3] annulation of para-quinamines: access to functionalized 1,2,4-triazinone derivatives.

An unprecedented [3+3]-annulation of p-quinamines and nitrile imines was developed, affording a series of 1,2,4-triazinone derivatives in moderate to excellent yields with excellent diastereoselectivity. This cycloaddition expands the scope of p-quinamines to the construction of six-membered nitrogen-containing heterocyclic compounds.