We report herein sharp physical evidence, i.e., single-crystal X-ray diffraction and 1H-NMR spectral data, confirming that quaternary ammonium species interact with anions via a set of directional ion–dipole cooperative +N-C-H unusual H-bonding interactions not pure non-directional ionic electrostatic interactions. This finding, which has been often invoked by calculations, is substantiated the...

The complex [Tpm(*,Br)Cu(NCMe)]BF4 (Tpm(*,Br) = HC(3,5-Me2-4-Br-pyrazolyl)3) catalyses the aziridination of alkenes and the amidation of cyclic ethers with chloramine-T as the nitrene source and the ionic liquid [bmim]PF6 as the reaction medium (bmim = 1-n-butyl-3-methylimidazolium). High conversions have been obtained over several cycles of catalyst recovery and reuse.

The first example of a triply cyclometalated homopolynuclear tri-Ir(III) complex with additional carbene donors is presented. Cooperative catalysis and the interplay between homogenous and heterogeneous catalyses are discussed for the tri-Ir(III) complex and a related non-cyclometalated tri-Pd(II) complex.

The imido-hydrido complex (ArN)Mo(H)(Cl)(PMe(3))(3) catalyses a variety of hydroboration reactions, including the first example of catalytic addition of HBCat to nitriles to form the bis(borylated) amines RCH(2)N(BCat)(2). The latter species easily undergoes chemoselective coupling with aldehydes R'C(O)H to yield imines RCH(2)N=C(H)R'.

Gallic acid efficiently catalyses radical arylations in water-acetone at room temperature. This methodology proved to be versatile and scalable. Therefore, it constitutes a greener alternative to arylation. Moreover, considering that gallic acid is an abundant vegetable tannin, this work also unleashes an alternative method for the reutilisation of bio-wastes.

Lipozyme TL IM immobilized on silica catalyses the deacylation of 4-C-acyloxymethyl-3,5-di-O-acyl-1,2-O-(1-methylethylidene)-beta-L-threo-pentofuranose to form 3,5-di-O-acyl-4-C-hydroxymethyl-1,2-O-(1-methylethylidene)-alpha-d-xylo-pentofuranose in a highly selective and efficient manner.

The dihydride pincer complex [IrH2(POCOP)] reacts with surface silanols of mesoporous silica (SBA-15) to give the coordinatively unsaturated, yet stable hydridesiloxo Ir(III) species [IrH(O-SBA-15)(POCOP)]. The silica-grafted complex catalyses the hydrogenation of ethene and propene at low temperature and pressure without prior activation.

The well-defined complex [Tpm(*,Br)Cu(NCMe)]BF(4) efficiently catalyses the [3+2] cycloaddition between alkynes and N-sulfonylazides under mild conditions, with conversions comparable to others obtained with in situ generated catalytic systems previously described for this transformation.

Nε-Trimethyllysine hydroxylase (TMLH) catalyses the first step in mammalian biosynthesis of carnitine, which plays a crucial role in fatty acid metabolism. The stereochemistry of the 3-hydroxy-Nε-trimethyllysine product of TMLH has not been defined. We report enzymatic and asymmetric synthetic studies, which define the product of TMLH catalysis as (2S,3S)-3-hydroxy-Nε-trimethyllysine.

It was proved that a judicious choice of counteranion played a prominent role in Cu(II) catalysis for enantioselective boron conjugate additions in water; the use of Cu(OH)2 renders heterogeneous catalysis, whereas Cu(OAc)2 renders homogeneous catalysis; cyclic dienones underwent a remarkable switch of regioselectivity between 1,4- and 1,6-modes of the additions through these catalyses.