Solid-Phase Synthesis with Resin-Bound Triarylbismuthanes

Significance

The authors have developed a multi-step solid-phase organic synthesis with a ­resin-bound bismuth linker. Thus, the reaction of the resin-bound bismuthane 1 with p-chloro­phenyl boronic acid was performed in the presence of Pd₂(dba)₃, P(t-Bu)₃, and KF in THF to give resin 2. Traceless cleavage was performed using TFA-CH₂Cl₂ (1:1) at room temperature to afford ­4-chlorobiphenyl in 58% yield over two steps. On the other hand, the biphenyl was cleaved by bromo-debismuthylation from the resin-bound bismuthane by treatment with a CH₂Cl₂ solution of bromine. 3-Bromo-4′-chlorobiphenyl was obtained in 83% yield from the reaction of 2 with bromine.