The aminocarbene group (CO) 5 Cr═C(NMe 2 ) behaves as a weak electron acceptor, with values of Hammett constants σ p roughly 0 and σ m = 0.14. These values are about the same as that for the SMe group. ... Benzoic acids 2a and 2b, bearing the (CO) 5 Cr═CN(CH 3 ) 2 group in the p- and m-position, and the corresponding benzoic acids 2c and 2d, in which the rotation of the aminocarbene moiety was blocked by the presence of a methyl group, were prepared ...
