title: Enantioselective Reactions of 2-Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho-Quinone Methide Intermediates.
abstract: We report herein a dynamic kinetic resolution (DKR) involving ortho-quinone methide (o-QM) intermediates. In the presence of Et3N and the cinchonine-derived nucleophilic catalyst D, the DKR of 2-sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57-79 % yield with good to excellent enantioselectivity (85-95 % ee). Furthermore, with 2-(tosylmethyl)sesamols or 2-(tosylmethyl)naphthols, from which stable o-QM substrates can be generated, a formal [4+2] cycloaddition delivered 4-aryl- or alkyl-substituted chromans with excellent enantioselectivity (88-97 % ee).
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
authors.forename: Wengang
authors.initials: W
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.|Graduate University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
authors.forename: Can
authors.initials: C
authors.lastname: Li
keywords: benzylic sulfones; chromans; cycloaddition; dynamic kinetic resolution; ortho-quinone methides