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Palladium‐Catalyzed Asymmetric [8+2] Dipolar Cycloadditions of Vinyl Carbamates and Photogenerated Ketenes
Author(s) -
Zhang QunLiang,
Xiong Qin,
Li MiaoMiao,
Xiong Wei,
Shi Bin,
Lan Yu,
Lu LiangQiu,
Xiao WenJing
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202005313
Subject(s) - enantioselective synthesis , stereocenter , cycloaddition , chemistry , palladium , ketene , catalysis , combinatorial chemistry , conjugated system , stereoselectivity , organic chemistry , polymer
Higher‐order cycloadditions, particularly [8+2] cycloadditions, are a straightforward and efficient strategy for constructing significant medium‐sized architectures. Typically, configuration‐restrained conjugated systems are utilized as 8π‐components for higher‐order concerted cycloadditions. However, for this reason, 10‐membered monocyclic skeletons have never been constructed via catalytic asymmetric [8+2] cycloaddition with high peri‐ and stereoselectivity. Here, we accomplished an enantioselective [8+2] dipolar cycloaddition via the merger of visible‐light activation and asymmetric palladium catalysis. This protocol provides a new route to 10‐membered monocyclic architectures bearing chiral quaternary stereocenters with high chemo‐, peri‐, and enantioselectivity. The success of this strategy relied on the facile in situ generation of Pd‐containing 1,8‐dipoles and their enantioselective trapping by ketene dipolarophiles, which were formed in situ via a photo‐Wolff rearrangement.