Pd₂dba₃/P(t-Bu)₃H.BF₄/Cy₂NMe Catalyzed Heck Coupling in Synthesis of 3-Alkenyl-1H-Isochromen-1-Ones

An efficient catalytic system comprising of Pd₂dba₃/P(t-Bu)₃H.BF₄/Cy₂NMe –for the Heck coupling in the synthesis of 3-alkenyl isochromen-1-ones, 3 has been developed. Air stable alkyl phosphonium salt, [(t-Bu)₃Ph]BF₄ was found to be vital for the activation of 3- chloroisochromen-1-ones, 1 in regio-selective Heck coupling reactions. The technique has additionally been reached out to typharin, penicilisorin and artemidin analogs.