Organocatalytic asymmetric Friedel-Crafts alkylation/cyclization cascade reaction of 1-naphthols and alpha,beta-unsaturated aldehydes: an enantioselective synthesis of chromanes and dihydrobenzopyranes.
An enantioselective Friedel-Crafts alkylation/cyclization cascade reaction of 1-naphthols and alpha,beta-unsaturated aldehydes promoted by diphenylprolinol ether has been developed. The method affords one-pot access to chiral and synthetically useful chromanes and dihydrobenzopyranes in high yields and enantioselectivities from readily available compounds. In addition, the addition/cyclization products could be afterward transformed to various natural products and biologically active derivatives. On the basis of the experimental results and the observed absolute configurations of the products, a plausible mechanism has been proposed to explain the origin of the activation and the asymmetric induction.
Hong
Liang
L
State Key Laboratory of Applied Organic Chemistry and Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, China.
Wang
Lei
L
Sun
Wangsheng
W
Wong
Kwokyin
K
Wang
Rui
R
D000447:Aldehydes / Q000737:chemistry*; D000478:Alkylation; D001578:Benzopyrans / Q000737:chemistry*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D002839:Chromans / Q000737:chemistry*; D003500:Cyclization; D015195:Drug Design; D008956:Models, Chemical; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature; D013997:Time Factors
D000447:Aldehydes; D001578:Benzopyrans; D002839:Chromans; D009284:Naphthols; C029141:2,2,5,7,8-pentamethyl-1-hydroxychroman; D010100:Oxygen