Synthesis of Pinacolylboronate-Substituted Stilbenes and their application to the synthesis of boron capped polyenes

A series of novel 4,4,5,5-tetramethyl-2-(4-substitutedstyrylphenyl)-1,3,2 dioxaborolane derivatives has been synthesized. 4-(4,4,5,5-tetramethyl-1,3,2-dioxaboratophenyl)-methyl triphenylphosphonium bromide (4) was treated with 3 equiv of tBuONa, various aldehydes in the presence of DMF, and stirred at room temperature 4-6 h to yield the corresponding boron containing stilbene derivatives 1a-n in 71-94% yields. A one-pot protocol transformation has also been developed and used this methodology to synthesize boron containing resveratrol analogues. Simple and clean reactions, high yield of the products are the salient features of this methodology. We used this reaction to synthesize the boron capped polyenes. These boron containing polyene systems are potential intermediate to synthesize conjugated polyene as new material for LCD (Liquid Crystal Display) technology. The biological testing of these compounds is currently underway to identify potential therapeutic for Neurodegenerative diseases.