Ligand-free Iron(II)-Catalyzed N-Alkylation of Hindered Secondary Arylamines with Non-activated Secondary and Primary Alcohols <i>via</i>
a Carbocationic Pathway
作者:Onkar S. Nayal、Maheshwar S. Thakur、Manoranjan Kumar、Neeraj Kumar、Sushil K. Maurya
DOI:10.1002/adsc.201701183
日期:2018.2.15
Secondary benzylic alcohols represent a challenging class of substrates for N‐alkylation of amines. Herein, we describe an iron(II)‐catalyzed eco‐friendly protocol for N‐alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of the known borrowinghydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self‐condensation
possess 3-allyl and 3-amino simultaneously, was first achieved by employing an intermolecular [2,3]-sigmatropic rearrangementreaction between diazooxindoles and tertiary allylic amines. Utilizing readily available allylamines as the nitrogen and allyl source concurrently, a wide range of bio-active 3-allyl-3-(amino)oxindoles were obtained in excellent yields under very mild reaction conditions; meanwhile