NEW SYNTHESIS SF FUNCTIONALIZED CHROMIUM CARBENE COMPLEXES USING ZINCORGANOMETALLICS

The reaction of functionalized dialkylzincs with photochemically gener ated Cr(CO)(5) . THF affords, after carbonylation and methylation usin g Meerwein's reagent, polyfunctional chromium carbene complexes in 35% -45% overall yield. The hydroboration of the unsaturated chromium carb ene complex 4e followed by a boron-zinc exchange mediated by diethylzi nc provides the dialkylzinc 6 bearing a chromium carbene functionality . This was reacted with deuterium oxide and iodine, affording the expe cted chromium carbene complexes in 67% and 43% yields, respectively.