TY - JOUR T1 - N-heterocyclic carbene catalysis exploiting oxidative imine umpolung for the generation of imidoyl azoliums JF - Journal of Organic Chemistry Y1 - 2020 A1 - Das, Tamal Kanti A1 - Madica, Krishnaprasad A1 - Krishnan, Jagadeesh A1 - Marelli, Udaya Kiran A1 - Biju, Akkattu T. AB -

Although NHC-catalyzed umpolung of imines are known, the related reactions under oxidative conditions are limited. Described herein is the two-step process involving the initial formation of aldimines from the corresponding aldehydes and 2-amino benzyl alcohols followed by NHC-catalyzed cyclization proceeding via the imidoyl azoliums under oxidative conditions. The reaction allowed the synthesis of trifluoromethylated 3,1-benzoxazines in good yields and broad scope. The role of NHC in the intramolecular cyclization and preliminary mechanistic experiments are also provided.

VL - 85 IS - 7 U3 -

Foreign

U4 -

4.335

ER -