Chemists Seek Greater Recognition for Catalysis

Can [M(H)2(H2)(PXP)] Pincer Complexes (M=Fe, Ru, Os; X=N, O, S) Serve as Catalyst Lead Structures for NH3 Synthesis from N2 and H2?

“…However, the activation energy for this reaction of 46.2 kcal mol À1 indicates the reaction is not possible in practice (Scheme 2c). All computationally derived results for ligand system a are in accord with our repeated experimental attempts to produce NH 3 in the presence of N 2 , H 2 , and catalyst precursor [Ru(H) 2 …”

“…[2] Significant efforts, many of them driven by an attempt to understand biological nitrogen reduction, have been made to synthesize and characterize transition-metal complexes that bond with and activate the N 2 molecule. A wealth of metal complexes (for example, titanium, [3] zirconium, [4, 9c] vanadium, [5] molybdenum, [6] and iron complexes [7] ) were shown to bond with and activate the N 2 molecule to varying extents, some of them even breaking the N À N structure motif completely.…”

Anti‐Markovnikov Hydrofunctionalization of Olefins Mediated by Rhodium–Porphyrin Complexes

“…[10] This transformation was highly regioselective, and in all cases the less-substituted metal-alkyl species was the only insertion product observed by 1 H NMR spectroscopy. [10] Furthermore, yields remained excellent in the presence of a diverse array of functional groups, including alcohols, aldehydes, carboxylic acids, sulfonamides, and nitroalkanes (Table 1, entries [1][2][3][4][5]. This extraordinary functional-group tolerance is particularly notable because the insertion mechanism involves reactive Rh II radicals as intermediates.…”

E–H Bond Activation of Ammonia and Water by a Geometrically Constrained Phosphorus(III) Compound

“…[22] In addition to these high profile examples,r ecent studies have shown that complexes of phosphorus(III) with distorted geometry can cleave arange of polarized EÀHbonds (E=Oor N). Studies by Arduengo et al and Radosevich and coworkers have shown that the planar T-shaped phosphorus system, A,f acilitates the oxidative addition of ammonia, primary amines,and alcohols ( Figure 1).…”