@article {46899, title = {N-heterocyclic carbene catalysis exploiting oxidative imine umpolung for the generation of imidoyl azoliums}, journal = {Journal of Organic Chemistry}, volume = {85}, year = {2020}, month = {APR }, pages = {5114-5121}, type = {Article}, abstract = {

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.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.0c00360}, author = {Das, Tamal Kanti and Madica, Krishnaprasad and Krishnan, Jagadeesh and Marelli, Udaya Kiran and Biju, Akkattu T.} }