posted on 2020-05-07, 18:17authored byBruno
A. Martek, Martin Gazvoda, Damijana Urankar, Janez Košmrlj
Simultaneous introduction
of two different palladium (pre)catalysts,
one tuned to promote oxidative addition to (hetero)aryl bromide and
another to activate terminal alkyne substrate, leads to productive
Pd–Pd transmetalation, subsequent reductive elimination, and
formation of disubstituted alkyne. This conceptually novel rational
design of copper-free Sonogashira reaction enabled facile identification
of the reaction conditions, suitable for the synthesis of alkyl, aryl,
and heteroaryl substituted alkynes at room temperature with as low
as 0.125 mol % total Pd loading.