SINGLET METHYLENE AND HALOCARBENES INSERTIONS INTO POLAR N–H BONDS OF AMINES

The insertion of singlet 1CH2 , 1CHF , and 1CF2 into polar N–H bonds of RNH2 ( R = –CH3, –C2H5, –C3H7 or –CH(CH3)2 ) has been investigated at HF, MP2, and DFT levels using 6-31g (d, p) basis set. The insertions proceed via a two-step mechanism. The potential energy surface exploration identifies an ylide formation followed by the 1,2-proton shift concertedly giving the secondary amine. The barrier height varies with the type of carbene and amine. HOMO of amines and LUMO of carbenes control the initial interactions and it is confirmed by NBO charge analysis.