Abstract
N-Triflylphosphoramides (NTPA), have become increasingly popular catalysts in the development of enantioselective transformations as they are stronger Brønsted acids than the corresponding phosphoric acids (PA). Their highly acidic, asymmetric active site can activate difficult, unreactive substrates. In this review, we present an account of asymmetric transformations using this type of catalyst that have been reported in the past ten years and we classify these reactions using the enantio-determining step as the key criterion. This compendium of NTPA-catalysed reactions is organised into the following categories: (1) cycloadditions, (2) electrocyclisations, polyene and related cyclisations, (3) addition reactions to imines, (4) electrophilic aromatic substitutions, (5) addition reactions to carbocations, (6) aldol and related reactions, (7) addition reactions to double bonds, and (8) rearrangements and desymmetrisations. We highlight the use of NTPA in total synthesis and suggest mnemonics which account for their enantioselectivity.
Highlights
Making molecules with high levels of stereoselectivity is a central challenge in organic chemistry
We present an account of asymmetric transformations using this type of catalyst that have been reported in the past ten years and we classify these reactions using the enantio-determining step as the key criterion
We highlight the use of NTPA in total synthesis and suggest mnemonics which account for their enantioselectivity
Summary
Making molecules with high levels of stereoselectivity is a central challenge in organic chemistry. During this time, he worked on asymmetric catalysis with Brønsted acids and molecular modelling. Since the first reports from the groups of Akiyama and Terada,[11,12,13,14] these catalysts have been widely used in asymmetric synthesis.[15] Several reviews are devoted to PA and to the chemical transformations they catalyse These include Mannich reactions,[16] Diels–Alder reactions,[17] cycloadditions,[18] multicomponent reactions,[19] additions to carbonyl groups,[20] additions to imines[21,22] and C–C bond forming reactions.[23,24] heterogeneous Brønsted acid catalysis by PA has been reported in an enantioselective fashion.[25] the field of NTPA-catalysed reactions has not been reviewed exhaustively. The NTPA-catalysed reactions published from 2006 to 2010 are summarised in Scheme 2.26,28–34,35–40
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
