Facile Synthesis and Palladium-Catalyzed Cross-Coupling Reactions of 2,3-Bis(pinacolatoboryl)-1,3-butadiene

摘要

Treatment of 1,1-bis(pinaco-latoboryl)ethene with an excess of 1-bromo-1-lithioethene gave 2,3-bis(pina-colatoboryl)-1,3-butadiene in high yield.Palladium-catalyzed cross-coupling of the resulting diborylbutadiene with aryl iodides took place smoothly in the presence of a catalytic amount of Pd(OAc)2/PPh3 and aqueous KOH to give 2,3-diaryl-1,3-butadienes in good yields.The coupling reaction with commercially available 4-acetoxyphen-ylmethyl chloride under the same con-ditions followed by hydrolysis of the acetyl groups gave anolignanB in a one-pot manner.A variety of[3]-to[6]dendralenes were synthesized by palladium-catalyzed coupling of the diene or 1,1-bis(pinacolato)borylethene with alkenyl or dienyl halides,respectively,in good yields.