E,Z-Selectivity in the reductive cross-coupling of two benzaldehydes to stilbenes under substrate control

Abstract

Unsymmetrical E- and Z-stilbenes can be synthetized from two differently substituted benzaldehydes in a MesP(TMS)Li-promoted reductive coupling sequence. Depending on the order of addition of the two coupling partners, the...

Recent advances in synthesis of stilbene derivativesviacross-coupling reaction

“…In this work, they used MesP(TMS)Li in a reductive coupling process for the synthesis of unsymmetrical E - and Z -enriched stilbenes 32c and 33c from two differently substituted benzaldehydes (Scheme 40). 55 In such a one-step phosphorus-mediated cross-coupling process, due to the sequential addition of two coupling partners at different stages of the sequence, different E - and Z -directing effects on the two aldehydes were achieved. As seen in the left column of the chart where aldehyde 32b features an electron-donating group (EDG), or aldehyde 33b has an ortho -substituent, Z -enriched stilbenes were observed.…”

Synthesis of Stilbenes by Cyanide/Base-Mediated Coupling of Benzylic Chlorides and Alcohols

“…Benzylic sulfones can form the diarylethene motif when reacted with benzylic alcohols in the presence of a nickel catalyst and a base 5 or with benzylic quaternary ammonium salts and a base. 6 Two benzaldehydes can undergo reductive coupling with either MesP(TMS)Li 7 or B2Pin2 8 while a rhodium complex catalyzes the direct aerobic alkenylation of aromatic compounds with styrenes. 9 Visible light can be used to mediate the coupling of -nitrostyrenes and arylazo sulfones 10 as well as the coupling of -styrylboronic acids and arenediazonium salts.…”