Phosphite‐Catalyzed C−H Allylation of Azaarenes via an Enantioselective [2, 3]‐Aza‐Wittig Rearrangement. Issue 40 (29th August 2019)

• Record Type: Journal Article
• Authors: Motaleb, Abdul; Rani, Soniya; Das, Tamal; Gonnade, Rajesh G.; Maity, Pradip
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 40(2019)
• Page Start: 14104
• Page End: 14109
• Publication Date: 2019-08-29
• Subjects: asymmetric catalysis -- C−H allylation -- aza-Wittig rearrangement -- rearomatization -- TADDOL phosphites; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201906681
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A phosphite‐mediated [2, 3]‐aza‐Wittig rearrangement has been developed for the regio‐ and enantioselective allylic alkylation of six‐membered heteroaromatic compounds (azaarenes). The nucleophilic phosphite adducts of N‐allyl salts undergo a stereoselective base‐mediated aza‐Wittig rearrangement and dissociation of the chiral phosphite for overall C−H functionalization of azaarenes. This method provides efficient access to tertiary and quaternary chiral centers in isoquinoline, quinoline, and pyridine systems, tolerating a broad variety of substituents on both the allyl part and azaarenes. Catalysis with chiral phosphites is also demonstrated with synthetically useful yields and enantioselectivities. Abstract : Powered by rearomatization : The adduct of a nucleophilic chiral phosphite with an azaarene N‐allyl salt undergoes a stereoselective base‐mediated aza‐Wittig rearrangement. This method efficiently generates tertiary and quaternary chiral centers in isoquinoline, quinoline, and pyridine systems along with an alkene handle for further functionalization.