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A Facile Enantioselective Alkynylation of Chromones
Author(s) -
DeRatt Lindsey G.,
Pappoppula Mukesh,
Aponick Aaron
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201902405
Subject(s) - enantioselective synthesis , chemistry , alkynylation , ligand (biochemistry) , enol , protonation , catalysis , combinatorial chemistry , alkyne , silylation , organic chemistry , ion , biochemistry , receptor
The first catalytic enantioselective alkynylation of chromones is reported. In this process, chromones are silylated to form silyloxybenzopyrylium ions that lead to silyl enol ethers after Cu‐catalyzed alkyne addition using StackPhos as a ligand. The outcome of the reaction is impacted by distal ligand substituents with differing electronic character and it was found that successful reactions could be achieved with different ligand congeners by using different solvents. This sequence enables access to different products by protonation or further functionalization, thus increasing complexity in a divergent manner. The transformation is high yielding over a broad scope to provide a variety of useful chromanones in high enantioselectivity.