Catalytic Adaptive Recognition of Thiol (SH) and Selenol (SeH) Groups Toward Synthesis of Functionalized Vinyl Monomers

An unprecedented sustainable procedure was developed
to produce
functionalized vinyl monomers H2CC­(R)­(FG) starting
from a mixture of sulfur and selenium compounds as a functional group
donor (FG = S or Se). The reaction serves as a model for efficient
utilization of natural resources of sulfur feedstock in oil and technological
sources of sulfur/selenium. The catalytic system is reported with
amazing ability to recognize SH/SeH groups in the mixture and selectively
incorporate them into valuable organic products via wastes-free atom-economic
reaction with alkynes (HCCR). Formation of catalyst active
site and the mechanism of the catalytic reaction were revealed by
joint experimental and theoretical study. The difference in reactivity
of μ1- and μ2-type chalcogen atoms
attached to the metal was established and was shown to play the key
role in the action of palladium catalyst. An approach to solve a challenging
problem of dynamically changed reaction mixture was demonstrated using
adaptive tuning of the catalyst. The origins of the adaptive tuning
effect were investigated at molecular level and were found to be governed
by the nature of metal–chalcogen bond.