G. Doyle Daves

Preparation of 1-(tri-n-butylstannyl) furanoid glycals and their use in palladium-mediated coupling reactions

Abstract 1-(Tri-n-butylstannyl)furanoid glycals have been prepared for the first time by lithiation of the corresponding 3-O-unsubstituted glycals followed by reaction with tri-n-butylstannyl chloride. Furanoid glycals bearing an alkoxy (silyloxy) group at C-3 undergo elimination and furan formation. A 3-O-benzyl-1-(tri-n-butylstannyl)furanoid glycal was prepared from the 1-phenylsulfonyl furanoid glycal using tri-n-butylstannylhydride and AIBN. Stannylated furanoid glycals and iodoaglycon derivatives underwent palladium-mediated coupling to yield the corresponding 1-substituted furanoid glycals in good to excellent yields.

Palladium-Mediated Coupling Reactions of an Aminosubstituted Heterocycle. Direct Synthesis of C-Nucleosides Related to Adenosine

Abstract C-Nucleosides of the pyrazolo[1, 5-a]-1, 3, 5-triazine aglycon system have been prepared by palladium-mediated coupling of 8-iodopyrazolo[1, 5-a]-1, 3, 5-triazines. 4-(N, N-Diisobutyloxycarbonyl)amino-8-iodopyrazolo[1, 5-a]-1, 3, 5-triazine and the furanoid glycal 1, 4-anhydro-2-deoxy-3-O[(1, 1 dimethylethyl)diphenylsilyl]-D-erythro-pent-1-enitol coupled in the presence of catalytic palladium(0) to yield, after desilylation of the intermediate silyl enol ether, a C-glycoside analog of adenosine.

Efficient synthesis of 3H,5H-pyrrolo[3,2-d]pyrimidin-4-one

Palladium-catalysd cross-coupling of 4-iodo-6-methoxy-5-nitropyrimidine and trimethyl(tributylstannylethynyl)silane to form the corresponding 4-trimethylsilylethynylpyrimidine and subsequent construction of an annellated pyrrolo ring provides an efficient route to the pyrrolo[3,2-d]pyrimidine system.