The asymmetric bis-imido structure and the lability of the diethyl ether linkage in complex 1 provide a niobium complex that undergoes regioselective [4+2] cycloaddition reactions with an α,β-unsaturated ketone and cycloaddition reactions that involve bond formation to the MAD ligand (MonoAzabutaDiene). DFT calculations have been used to support an initial azametallacyclobutene intermediate in ...

The discovery of two new classes of catalysts for hydrazone and oxime formation in water at neutral pH, namely 2-aminophenols and 2-(aminomethyl)benzimidazoles, is reported. Kinetics studies in aqueous solutions at pH 7.4 revealed rate enhancements up to 7-fold greater than with classic aniline catalysis. 2-(Aminomethyl)benzimidazoles were found to be effective catalysts with otherwise challeng...

A combined computational and experimental investigation of three different Cp*CoIII systems used in combination with a base as catalysts “borrowing hydrogen” alkylations by secondary alcohols (ROH), resulting C–N or C–C bond formation, reveal the existence new pathway for alcohol activation, differing from existing paradigms oxidative ionic activations. The metal-coordinated alkoxide (OR) gener...

The first examples of the directed, boron-mediated aldol reaction between different ketones are presented. Transformation of a variety of ketones to their corresponding boron enolates with Chx2BCl/Et3N, followed by reaction with acceptor ketones in diethyl ether, and oxidation of the resultant boron aldolate (H2O2, MeOH/pH 7 buffer), provided the aldol addition products. The reaction was most f...

It was reported that there was a relationship between the acetate metabolism and TCA cycle in rumen epithelium of sheep. The present study was designated to elucidate how this relationship was influenced by starvation and alloxan treatment. The results obtained are summarized as follows. There was no effect of the addition of citrate or succinate on the "C transfer from "C-acetate into CO„gluco...

Abstract An asymmetric hydrogenation of enamines is efficiently catalysed by rhodium complexed with a fluorinated version the planar chiral paracyclophane-diphosphine ligand, Phanephos. This catalyst was shown to be very active, examples operating at just 0.1 mol% catalyst. then successfully adapted Direct Asymmetric Reductive Amination, leading formation several tertiary amines moderate ee, if...