Facile, mild, and highly enantioselective alkynylzinc addition to aromatic aldehydes by BINOL/N-methylimidazole dual catalysis.
The dual Lewis acid/base catalytic system, generated from N-methylimidazole (NMI), (R)-1,1'-bi-2-naphthol [(R)-BINOL], and Ti(OiPr)4, effectively catalyzes the enantioselective alkynylation of aldehydes in the presence of Et2Zn in good yields and excellent enantioselectivities of up to 94% ee at room temperature. The mild reaction conditions make it possible to use functional alkynes in this asymmetric addition.
Yang
Fei
F
Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China.
Xi
Peihua
P
Yang
Li
L
Lan
Jingbo
J
Xie
Rugang
R
You
Jingsong
J
D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D007093:Imidazoles / Q000737:chemistry*; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
D000447:Aldehydes; D000480:Alkynes; C406944:BINOL, naphthol; D007093:Imidazoles; D009284:Naphthols; C044736:phenylacetylene; D015032:Zinc; D000114:Acetylene; C018100:1-methylimidazole