ol8b02236_si_001.pdf (5.43 MB)
Brønsted Base-Catalyzed Reductive Cyclization of Alkynyl α‑Iminoesters through Auto-Tandem Catalysis
journal contribution
posted on 2018-08-15, 20:30 authored by Azusa Kondoh, Masahiro TeradaA novel
reductive cyclization of alkynyl α-iminoesters was
developed through auto-tandem catalysis with a Brønsted base
as the catalyst. The reaction system involves two mechanistically
different elementary processes, both of which are efficiently catalyzed
by an organosuperbase P2-tBu: the unprecedented reduction
of α-iminoesters with 1-dodecanethiol as the reductant to provide
α-aminoesters and the following intramolecular addition of ester
enolates to an alkyne. The operationally simple reaction under mild
conditions provides new efficient access to N-H indoline
derivatives, demonstrating the high potential of auto-tandem catalysis
with a Brønsted base as a methodology for organic synthesis.