ChemInform Abstract: Base‐Catalyzed Asymmetric α‐Functionalization of 2‐(Cyanomethyl)azaarene N‐Oxides Leading to Quaternary Stereocenters.

Abstract

A highly enantioselective α‐functionalization of 2‐(cyanomethyl)pyridine N‐oxides and pyrazine N‐oxides via conjugate addition of 4‐hydroxy‐4‐methylpent‐1‐en‐3‐one or α‐amination with di(tert‐butyl) or dibenzyl azodicarboxylate is developed.

Asymmetric α-Functionalization of 2-Alkyl Azaarenes: Synthesis of Tertiary Fluorides Having Vicinal Stereogenic Centers

“…Although the enantioselective construction of alkyl azaarenes having tertiary chiral centers has been attempted since 2012 by employing chiral Ni(II), Pd(II), and iminium ion catalysis (Scheme 1b), 5 the first synthesis of the alkyl azaarenes containing α-quaternary stereocenters was reported by Palomo et al in 2016 (Scheme 1c). 6 Quaternary stereocenters are ubiquitous in natural products, but their asymmetric construction is still a significant challenge due to the steric aided lower reactivity of the reaction center. Consequently, very few literature reports are available to synthesize quaternary alkyl azaarenes.…”