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A novel Ni(0) -catalyzed carboxylation of aryl tosylates with carbon dioxide has been achieved under moderate temperatures and atmospheric pressure. In this procedure, the active Ni(0) species is generated in situ by simply mixing the Ni(0) precatalyst [NiBr2 (bipy)] with an excess of manganese metal. This approach requires neither a glove-box nor the tedious preparation of sophisticated intermediate organometallic derivatives. This mild, convenient, and user-friendly process is successfully applied to the valorization of carbon dioxide and the synthesis of versatile reactants with broad tolerance of substituents.

The stereoconservative Staudinger ligation of unprotectedα‐ and β‐glycosyl azides with 2‐(diphenylphosphanyl)‐4‐fluorophenyl esters to afford α‐ and β‐N‐glycosyl amino acids is described. The ligation method works reliably well for unprotected β‐azides of the gluco, galacto and fuco series. Lower yields (ca. 50 %) were obtained with a β‐glucosyl‐N‐acetyl azide. The reaction of an α‐glucosyl azide also led to major improvements compared with the use of non‐fluorinated phosphanes. All the N‐glycosyl amino acid products can be isolated and byproducts removed from the crude reaction mixtures by simple water extraction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)