Revealing the Similarities of α,β‐Unsaturated Iminiums and Acylazoliums in Organocatalysis

Abstract

Scheme 15. Cascade reaction of amino benzaldehydes with 1 (a) and 2 (b). Scheme 16. Cascade reaction of pyrazolinoneswith 1 (a) and 2 (b). Scheme 17. Reaction of indoles with 1 (a) and 2 (b).

Mesoionic N-heterocyclic olefin catalysed reductive functionalization of CO2 for consecutive N-methylation of amines

“…It may be recalled that N-heterocyclic olefins 28 (NHOs), alkylidene derivatives of N-heterocyclic carbenes 29–31 (NHCs), have been emerging as metal-free catalysts for various organic transformations including CO 2 activation, polymerization, and hydrosilylation reactions. 32–35 Besides these NHOs, Hansmann and co-workers recently introduced a super nucleophilic mesoionic N-heterocyclic olefin (mNHO) 1 containing a polarised exocyclic double bond.…”

NHC‐Catalyzed Desymmetrization of N‐Aryl Maleimides Leading to the Atroposelective Synthesis of N‐Aryl Succinimides

“…In 2018, Wang and co‐workers reported the NHC‐catalyzed kinetic resolution of anilides for the C‐N axially chiral compounds, [11] where the reaction proceeds via the chiral α,β‐unsaturated acylazoliums [Scheme 1, Eq. (1)] [12] . Given the limitations of kinetic resolution strategies and considering the applications of C‐N axially chiral compounds, we envisaged the NHC‐catalyzed desymmetrization of N‐aryl maleimides as a strategy for the atom‐economic and atroposelective synthesis of N‐aryl succinimides [13] .…”

N-Heterocyclic Carbene-Catalyzed Formal [3+3] Annulation of Alkynyl Acylazoliums for the Synthesis of Benzofuro[3,2-b]pyridin-2-ones

“…4-(3-(Pyridin-2-yl)phenyl)-1-tosylbenzofuro [3,2-b]pyridin-2(1H)one (4). Yield: 12 mg, 49%; white solid.…”