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A short concise route to β-aminophosphine boranes is presented via the desymmetrization of prochiral phosphine boranes, forming P-chirogenic aldehydes that are rapidly transformed to the target compounds employing reductive amination under microwave irradiation. This sequence provides a modular route to P-chirogenic P,N ligands, and in addition, the intermediate aldehydes are versatile P-chiral building blocks for ligand design in general. An alternative pathway via the corresponding a-carboxyphosphines is also described. The ligands were subsequently evalutated in the asymmetric conjugate addition of diethylzinc to trans-β-nitrostyrene. [ABSTRACT FROM AUTHOR]

Abstract: An intermolecular Pauson–Khand reaction involving a carbohydrate scaffold having a pendant alkyne provides galactose derivatives with a cyclopentenone moiety in the C3-position in up to 85% yield. [Copyright &y& Elsevier]

Abstract: The reactivity of three polymer-bound cyclohexadienoic acid active esters was modified by complexation with iron tricarbonyl in order to evaluate their potential use as linker systems for solid phase chemistry. The best results were obtained with the tetrafluorophenol ester, which was slowly cleaved when 1equiv of amine was used, but could be rapidly cleaved with up to 94% yield when the amount of nucleophile was increased. [Copyright &y& Elsevier]

Abstract: Cationic iron carbonyl cyclohexadiene complexes were employed in the derivatization of the 3-OH position of unprotected and protected methyl β-d-galactopyranosides using two different approaches, giving access to galactopyranosides with an aromatic or cyclohexadienoic functionality in this position. [Copyright &y& Elsevier]

Abstract: Methyl β-d-galactoside was converted to the corresponding 3,4-O-stannylene acetal, which was selectively benzylated with 3-iodobenzyl bromide and coupled to a polymer-bound propargylic ether via a Sonogashira reaction. The polymer-bound carbohydrate substrate was cleaved from the resin with different carbon nucleophiles in a cobalt-mediated Nicholas reaction. The product 3-O-alkynylbenzyl galactosides were screened towards galectin-1, -3, -7, -8N and -9N in a competitive fluorescence polarisation assay. Particularly potent inhibitors were identified against galectin-7 with affinity enhancements up to one order of magnitude due to the 3-O-alkynylbenzyl moiety. [Copyright &y& Elsevier]