A catalytic process for the chemo- and regioselective functionalization of nonprotected carbohydrates has been developed. This novel process allows selective thiocarbonylation, acylation, and sulfonylation of a particular hydroxy group in a particular carbohydrate in the simultaneous presence of structurally similar carbohydrates such as anomers. In addition, the chemoselectivity can be switche...

A Rh(NHC) phosphonate complex reacts with the lipases cutinase and Candida antarctica lipase B resulting in the first (soluble) artificial metalloenzymes formed by covalent active site-directed hybridization. When compared to unsupported complexes, these new robust hybrids show enhanced chemoselectivity in the (competitive) hydrogenation of olefins over ketones.

2-Sulfonimidoylylidene tetrahydrofurans and 5-vinyl-2-sulfonimidoylylidene tetrahydrofurans were readily synthesized via a consecutive acylation/SN2 sequence with total regioand chemoselectivity from Johnson’s sulfoximine derivatives. The same consecutive reaction could also be applied to the expeditious synthesis of 6-sulfonimidoylmethyl-3,4-dihydro-2H-pyrans. © 2012 Elsevier Science. All righ...

We describe herein an unprecedented asymmetric α-amination of β-ketocarbonyls under aerobic conditions. The process is enabled by a simple chiral primary amine through the coupling of a catalytic enamine ester intermediate and a nitrosocarbonyl (generated in situ) derived from N-hydroxycarbamate. The reaction features high chemoselectivity and excellent enantioselectivity for a broad range of s...

We found that chemoselectivity of the crossed acyloin product is controlled by the adjustment of the aromatic aldehyde/aliphatic aldehyde ratio. Moreover, we observed the persistent catalytic activity of the homogeneous NHC catalyst in a solution due to NHC catalyst robustness.

FeCl(2) catalyzes the oxidative C-C cross-coupling of tertiary amines with terminal alkynes into propargylamines using (t-BuO)(2) as oxidant. The reaction can be applied to aromatic and aliphatic amines and alkynes without solvent. High chemoselectivity for aminomethyl groups is due to a steric factor.

The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C–O, C–N and C–C bonds in technical acetone, and in air. Good to excellent yields were obtained using low acid loading (typically 1 mol %) under simple reaction conditions and good chemoselectivity.