A Co(ii)-NNN pincer complex catalyzed directN-alkylation of anilines with alcoholsviahydrogen auto-transfer and selective acceptorless dehydrogenative coupling of benzylamines with alcohols affording imines with the liberation of molecular hydrogen and water is reported.

The synthesis, structural characterization, and properties of a new series of asymmetrically substituted bis(dithiolene) nickel(III) compounds [Bu4N][Ni(Phdt)2] (1) (Phdt = 2-Phenyl-1,2-dithiolate), [Bu4N][Ni(NO2Phdt)2] (2) (NO2Phdt = 2-( p-nitrophenyl)-1,2-dithiolate), [Bu4N][Ni(FPhdt)2] (3) (FPhdt = 2-( p-fluorophenyl)-1,2-dithiolate), [Bu4N][Ni(ClPhdt)2] (4) (ClPhdt = 2-( p-chlorophenyl)-1,2-dithiolate), and [Bu4N][Ni(BrPhdt)2] (5) (BrPhdt = 2-( p-bromophenyl)-1,2-dithiolate) have been described. All complexes 1- 5 exhibit absorptions in the near-infrared region; the shift of these absorption bands can be tuned by the choice of the substituents on the relevant dithiolene moieties. The substituents on the dithiolene moiety are also responsible for their structural diversities. The nature of the substituents on the dithiolene moiety play an important role in tuning the redox potentials along this series. The nitro derivative (compound 2) exhibits several redox couples in its cyclic voltammogram in contrast to the other compounds in this series. The synthesis and characterization of two asymmetrically halogen substituted tetrathiafulvalene (TTF) derivatives 4,4'-bis(4-chlorophenyl)-tetrathiafulvalene ClPhTTF (6) and 4,4'-bis(4-bromophenyl)-tetrathiafulvalene (BrPhTTF) (7) have been described. One of these compounds has been structurally characterized. Iodine treatment of the monoanionic Ni(III) compound [Bu4N][Ni(ClPhdt)2] (4) results in the formation of a neutral Ni(IV) complex [Ni(ClPhdt)2] (8). All monoanionic compounds 1- 5 are Ni(III) complexes, as evidenced by electron spin resonance spectroscopy. Interestingly, strong Cl...Cl interactions are observed in the solid state structures of the chlorinated compounds 6 and 8. Finally, the structural features of compound [Ni(ClPhdt)2] (8) and the TTF derivative ClPhTTF (6) are compared based on their enormous structural similarities, and the neutral compound [Ni(ClPhdt)2] (8) is classed as the "an inorganic counterpart of TTF".

Scheme1.Ni-catalyzedC ÀCbond-formingr eactions. a) Alkylation of unactivated carbonyl derivatives. b) Usual nickel catalysis. c) This work.[a] S.

A molecularly defined NNN-type cobalt pincer complex catalyzed semi-hydrogenation of unbiased alkynes to Z-selective alkenes is reported. The reaction operates at a low temperature (50–80 °C), phosphine ligand-free, and base-free conditions with no additive required.

No abstract