10.1002/anie.201705903
Angewandte Chemie International Edition
COMMUNICATION
provides the first photochemical route to C(sp)-S bond
architectures, and should complement existing photochemical
functionalizations as the thiol-ene (C(sp3)-S bond) and thiol-yne
(C(sp2)-S bond) reactions, which have been established as
important tools in the chemical sciences. The method exploits a
readily available and soluble organic photocatalyst that permits
exploiting continuous flow techniques. As such, facile and rapid
(30 min residence time) synthesis of thioalkynes on gram scale
is possible, and a wide range of electronically and sterically
diverse aromatic alkynes and thiols are viable coupling partners.
In addition, the first dual-catalytic macrocyclization was achieved
to prepare a 19-membered macrocycle, which represents, to the
best of our knowledge, the first incorporation of the thioalkyne
moiety into a macrocyclic scaffold. Considering the utility for new
chemoselective and functional group-tolerant thiol-based
coupling reactions, the method will provide access to new
thioalkyne architectures for application in medicinal chemistry,
chemical biology, and materials science.
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The authors acknowledge the Natural Sciences and Engineering
Research Council of Canada (NSERC), the NSERC CREATE
program in Continuous Flow Science, the Canadian Foundation
for Innovation for financial support for continuous flow
infrastructure and the Centre for Green Chemistry and Catalysis
(CGCC) for funding. Ms. Vanessa Kairouz is thanked for
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Keywords: photocatalysis • alkynyl sulfides • dual catalysis •
macrocycles • continuous flow
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