Asymmetric Synthesis of cis-3,4-Disubstituted Chromans and Dihydrocoumarins via an Organocatalytic Michael Addition/Hemiacetalization Reaction

作者：Enders Dieter^*; Wang Chuan; Yang Xuena; Raabe Gerhard

来源：Advanced Synthesis & Catalysis, 2010, 352(17): 2869-2874.

DOI：10.1002/adsc.201000659

• chromans
• 3,4-dihydrocoumarins
• hemiacetalization
• Michael addition
• organocatalysis

The organocatalytic domino Michael/hemiacetalization reaction between various aldehydes and ortho-nitrovinylphenols has been developed. Under the catalysis of diphenyl prolinol trimethylsilyl ether, cis-3,4-disubstituted chromanols are obtained in high to excellent yields (81-98%) and stereoselectivities (dr: 86:14 to >99:1, ee 96 to > 99%). The corresponding disubstituted chromans are available by dehydroxylation of the domino products in good to excellent yields (58-95%). Furthermore, oxidation of the domino products with pyridinium chlorochromate provided 3,4-dihydrocoumarins in good yields (65-83%) without any epimerization.

• 出版日期2010-11-22