Premium
Brønsted Base‐Catalyzed Umpolung Intramolecular Cyclization of Alkynyl Imines
Author(s) -
Kondoh Azusa,
Terada Masahiro
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201800219
Subject(s) - umpolung , moiety , carbanion , chemistry , nucleophile , imine , intramolecular force , electrophile , alkyne , catalysis , medicinal chemistry , stereochemistry , organic chemistry
A novel “umpolung” intramolecular cyclization of alkynyl imines, in which the electrophilic imine sp 2 ‐carbon formally serves as a nucleophilic site, was developed under Brønsted base catalysis. The reaction involves the unprecedented catalytic generation of α‐aminoester enolates from α‐iminoesters via the 1,2‐addition of the anion of a secondary phosphite to an imine moiety followed by the [1,2]‐rearrangement of a dialkoxyphosphoryl moiety from carbon to nitrogen, which is a formal umpolung process, and the intramolecular addition to an alkyne. This is a rare example of a [1,2]‐rearrangement of a dialkoxyphosphoryl moiety from carbon to nitrogen to generate an α‐amino carbanion and the first catalytic carbon–carbon bond forming reaction utilizing the resulting carbanion as a nucleophile.