Yang P,
Wang R.-X,
Huang X.-L,
Cheng Y.-Z,
You S.-L.
*
Shanghai Institute of Organic Chemistry, P. R. of China
Enantioselective Synthesis of Cyclobutane Derivatives via Cascade Asymmetric Allylic
Etherification/[2+2] Photocycloaddition.
J. Am.Chem. Soc. 2023;
145: 21752-21759
DOI:
10.1021/jacs.3c08792
Key words
iridium catalysis - chiral cyclobutanes - photocycloaddition - enantioselective cascade
reactions
Significance
The group of You reports an enantioselective synthesis of cyclobutane derivatives
via an iridium-catalyzed strategy under blue LED conditions. The wide functional group
tolerance with good to excellent diastereoselectivity (up to 12:1) and excellent enantioselectivity
(up to >99%) enhance the utility of this method. This reaction can be scaled to 8
mmol scale with similar efficiency.
Comment
The authors developed an efficient synthesis of chiral cyclobutanes, a key synthon
in organic synthesis of natural or biologically active molecules. The reaction proceeds
via a cascade reaction involving Ir-catalyzed asymmetric allylic etherification followed
by visible-light-induced [2+2] cycloaddition. This strategy used styrenyl acetates
lacking a directing group and straightforward set-up: all the starting materials and
catalysts are added simultaneously.
