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Iron‐Catalyzed Highly Enantioselective cis ‐Dihydroxylation of Trisubstituted Alkenes with Aqueous H 2 O 2
Author(s) -
Wei Jinhu,
Wu Liangliang,
Wang HaiXu,
Zhang Xiting,
Tse ChunWai,
Zhou CongYing,
Huang JieSheng,
Che ChiMing
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202002866
Subject(s) - dihydroxylation , enantioselective synthesis , chemistry , alkene , catalysis , ligand (biochemistry) , hydrogen peroxide , diamine , medicinal chemistry , aqueous solution , stereochemistry , organic chemistry , biochemistry , receptor
Reliable methods for enantioselective cis ‐dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis ‐α‐[Fe II (2‐Me 2 ‐BQPN)(OTf) 2 ], which bears a tetradentate N 4 ligand (Me 2 ‐BQPN=( R , R )‐ N , N′ ‐dimethyl‐ N , N′ ‐bis(2‐methylquinolin‐8‐yl)‐1,2‐diphenylethane‐1,2‐diamine), was prepared and characterized. With this complex as the catalyst, a broad range of trisubstituted electron‐deficient alkenes were efficiently oxidized to chiral cis ‐diols in yields of up to 98 % and up to 99.9 % ee when using hydrogen peroxide (H 2 O 2 ) as oxidant under mild conditions. Experimental studies (including 18 O‐labeling, ESI‐MS, NMR, EPR, and UV/Vis analyses) and DFT calculations were performed to gain mechanistic insight, which suggested possible involvement of a chiral cis ‐Fe V (O) 2 reaction intermediate as an active oxidant. This cis ‐[Fe II (chiral N 4 ligand)] 2+ /H 2 O 2 method could be a viable green alternative/complement to the existing OsO 4 ‐based methods for asymmetric alkene dihydroxylation reactions.