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Pd-catalyzed carbonylative cross-coupling reactions of 2-iodoglycals have been developed for the synthesis of sugar-based arylones and ynones using formic acid as the carbonyl source. Whereas acetyl-protected arylones lead to the formation of highly substituted furan derivatives in the presence of Lewis acid, benzyl-protected arylones furnished the 3-deoxy sugar derivative. In the presence of nucleophiles, an attack took place on the C-1 or C-3 carbon regio- and stereoselectively depending on the nature of the nucleophiles.

Pd catalyzed carbonylative reaction of 2-iodo-glycals has been developed taking formic acid as a carbonyl source for the synthesis of 2-carboxylic acids of sugars by the hydroxycarbonylation strategy. The methodology was successfully extended to the synthesis of 2-formyl glycals by using a reductive carbonylation approach. Both ester and ether protected glycals undergo the reaction and furnished sugar acids in good yield which is otherwise not possible by literature methods. The C-2 sugar acids were successfully utilized for the construction of 2-amido glycals, 2-dipeptido-glycal by Ugi reaction and C-1 and C-2 branched glycosyl esters. a Reaction conditions: 1a (0.18 mmol), 2a (0.36 mmol), Pd(OAc) 2 (0.009 mmol), L2 (0.018 mmol), N,N 0 -dicyclohexylcarbodiimide (DCC) (0.18 mmol), triethylamine (0.36 mmol) at 90 C for 2 h. b Yield of isolated product. Pd 5 mol% and ligand 10 mol% were used. Ratio of 3a and 3a 0 and conversion were determined through 1 H NMR.

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