Mckenna, Jeffrey, Jackson, Kelvin E, Mortimer, Claire L, Odell, Barbara, Claridge, Timothy D W, Paton, Robert S and Hodgson, David M (2015) α- and α'-Lithiation–Electrophile trapping of N-thiopivaloyl and N-t-butoxythiocarbonyl α-substituted Azetidines: rationalisation of the differing regioselectivity using NMR and computation. Journal Organic Chemistry.

Abstract

1H NMR and computational analyses provide insight into the regiodivergent (α- and α'-) lithiation−electrophile trapping of N-thiopivaloyl and N-t-butoxythiocarbonyl α-alkylazetidines. The magnitudes of the rotation barriers in these azetidines indicate that rotamer interconversions do not occur at the temperature and on the timescale of the lithiations. The NMR and computational studies support the origin of regioselectivity as being thiocarbonyl-directed lithiation from the lowest energy amide-like rotameric forms (cis for N-thiopivaloyl and trans for N-t-butoxythiocarbonyl).

Item Type:	Article
Date Deposited:	26 Apr 2016 23:45
Last Modified:	26 Apr 2016 23:45
URI:	https://oak.novartis.com/id/eprint/26281