Cross with allyl phosphonate

Scheme 3-61. Copper/chiral carbene-catalyzed cross-coupling of y-silyl-substituted allyl phosphonates with organozinc reagents.

AUcynylstannanes can cross-couple with a variety of other functional groups employing the Stille protocol. Couphng to acyl chlorides is a well-known procedure that affords aUcynylketones in respectable yields. Other reports include alkynyltin cross-couplings with a-haloethers and a-halocarbonyls, enol phosphinates and phosphonates, alkenyl(phenyl)iodonium salts, alkynyl halides, and allyl hahdes (Table 9.18). Alkynylstannanes have also been shown to cross-couple with iron halides under the Stille conditions to effectively form iron-carbon bonds. 

Kazmaier and Jena have presented syntheses of stannylated, allyl (86) and vinylphosphonates (87) by molybdenum-catalyzed hydrostannation of the corresponding propargyl- (84) and alkynylphosphonate (85) derivatives (Scheme 27). " The stannylated phosphonates, obtained with high regios-electivities, were applied as building blocks in further modifications, such as Pd-catalyzed cross coupling reactions or iodination. 

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