An efficient catalytic method for hydrophosphination of heterocumulenes with diethylzinc as precatalyst without a solvent

Commercially available compound ZnEt₂ acts as an efficient precatalyst for the solvent-free hydrophosphinations of heterocumulenes using Ph₂PH as reagent. As far as we knew, this has been not reported in group 12 metal catalyzing reactions. A suggested mechanism of this reaction is explored, and the intermediate [{Ph₂PC(NⁱPr)₂}ZnEt]₂ is obtained and characterized by a single-crystal X-ray structural analysis.

Biocatalytic Approach to Chiral β-Nitroalcohols by Enantioselective Alcohol Dehydrogenase-Mediated Reduction of α-Nitroketones

Chiral β-nitroalcohols are important building blocks in organic chemistry. The synthetic approach that is based on the enzyme-mediated reduction of α-nitroketones has been scarcely considered. In this work, the use of commercial alcohol dehydrogenases (ADHs) for the reduction of aromatic and aliphatic nitroketones is investigated. High conversions and enantioselectivities can be achieved with two specific ADHs, affording either the (S) or (R)-enantiomer of the corresponding nitroalcohols. The reaction conditions are carefully tuned to preserve the stability of the reduced product, and to avoid the hydrolytic degradation of the starting substrate. The further manipulation of the enantioenriched nitroalcohols into Boc-protected amminoalcohols is also described.

Application of chiral bi- and tetra-dentate bispidine-derived ligands in the copper(ii)-catalyzed asymmetric Henry reaction

Rationalized bispidinone-based ligands were reacted with copper(ii) salts, which afforded effective catalysts for asymmetric Henry reactions.