title: Aryl bromides as inexpensive starting materials in the catalytic enantioselective arylation of aryl aldehydes: the additive TMEDA enhances the enantioselectivity.
abstract: We used aryl bromides as inexpensive starting materials to enantioselectively arylate aldehydes in one pot. Aryl bromides readily transfer aryls to aryllithiums with n-butyllithium, successively to triarylaluminums with aluminum chloride, and then to aryltitaniums with titanium isopropoxide. Finally aryltitaniums arylate aldehydes catalyzed by (S)-H8-BINOL-Ti(Oi-Pr)2 in excellent yields and enantioselectivities. The additive TMEDA evidently suppresses the racemic background reaction promoted by LiCl generated from salt metathesis. This procedure represents a cost-effective and operationally convenient method for enantioenriched diarylmethanols.
authors.affiliation: Institute of Biochemistry & Molecular Biology, School of Life Sciences, Lanzhou University , Lanzhou 730000, China.
authors.forename: Yong-Xin
authors.initials: YX
authors.lastname: Yang
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Yan-E
authors.initials: YE
authors.lastname: Jia
authors.forename: Pei
authors.initials: P
authors.lastname: Wang
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Zhuo
authors.forename: Xian-Tao
authors.initials: XT
authors.lastname: An
authors.forename: Chao-Shan
authors.initials: CS
authors.lastname: Da
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D056831:Coordination Complexes; D006843:Hydrocarbons, Chlorinated; D009942:Organometallic Compounds; C450681:phenyllithium