Trimethylsilanolate-Promoted Activation of Alkynyl Trimethylsilanes: Hiyama-Type Sonogashira Cross-Coupling for the Synthesis of Arylene-Ethynylene-Linked Porphyrin Arrays.

To synthesize -ethynylene-conjugated porphyrin arrays, the Sonogashira cross-coupling reaction is straightforward to construct the C(sp)-C(sp) bonds, but the reaction is often accompanied by side reactions such as the Glaser homocoupling. The rate-determining oxidative addition step results in the unexpected kinetic competition with the Glaser homocoupling, which is desired to be circumvented. We here propose two sets of improved strategies for the synthesis of arylene-ethynylene-linked porphyrin arrays from the -brominated porphyrin and alkynes.