The first Ni-promoted prototype reaction based on the tandem C-H activation of heteroarenes with alkene isomerization is demonstrated, leading to the branched hydroheteroarylation products. Simultaneously, the reaction selectivity can be chemically switched to linear adducts through Ni-Al tandem catalysis.

RuCl 2 (PTA) 4 ] (PTA = 1,3,5-triaza-7-phosphaadamantane) was found to be a highly active catalyst for aqueous phase nitrile hydration at 100 • C in air. Near quantitative conversion of aromatic, alkyl, and vinyl nitriles to their corresponding amides was observed. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Some amides were isolated by simple decantation from the aqueous phase catalyst. Catalyst loading down to 0.001 mol% was examined with turnover numbers as high as 22 000 observed. The catalyst was stable for weeks in solution and could be reused more than five times without significant loss of activity.Amides are versatile and important synthetic intermediates used in the production of a variety of plastics, detergents, lubricants, and polymers. 1,2 Traditional methods of hydrating nitriles to amides involve the use of strong bases or acids under harsh conditions, often inducing undesired hydrolysis to carboxylic acids. 1-5 During neutralization salt formation can lead to contamination, separation, and pollution problems. 1-3 Moreover, poor tolerance for sensitive functional groups is often observed under such conditions. 1-3 A variety of transition metal complexes have been developed as efficient catalysts for nitrile hydration in organic media often with air-sensitive or non-recyclable catalysts. 1-7 Water, with its unique properties, has seen increased use as a solvent in stoichiometric and catalytic reactions. 8 Recently several aqueous homogeneous 9-11 and heterogeneous 12-15 nitrile hydration reactions have been reported under inert atmosphere.One common mechanistic pathway proposed for the hydration of nitriles involves nitrile coordination to a metal followed by nucleophilic attack by water on the nitrile carbon. 1 Recent studies have shown that nucleophilic attack can be promoted by activating water via hydrogen bonding to a functionalized ligand. 9-12,16-18 † Electronic supplementary information (ESI) available: Experimental details including nitrile hydration and catalyst recycling procedures, 31 P{ 1 H} NMR spectrum of the reaction mixture, and GC chromatogram, 1 H and 13 C{ 1 H} NMR spectra of isolated amides. See

The synthesis and structures of a series of new water-soluble phosphine ligands based on 1,3,5-triaza-7-phosphaadamantane (PTA) are described. Insertion of aldehydes or ketones into the C-Li bond of 1,3,5-triaza-7-phosphaadamantan-6-yllithium (PTA-Li) resulted in the formation of a series of slightly water-soluble beta-phosphino alcohols (PTA-CRR'OH, R = C6H5, C(6)H(4)OCH(3), ferrocenyl; R' = H, C(6)H(5), C(6)H(4)OCH(3)) derived from the heterocyclic phosphine PTA. Insertion of CO(2) yielded the highly water-soluble carboxylate PTA-CO(2)Li, S(2)5 degrees approximately 800 g/L. The compounds have been fully characterized in the solid state by X-ray crystallography and in solution by multinuclear NMR spectroscopy. The addition of PTA-Li to symmetric ketones results in a racemic mixture of PTA-CR(2)OH ligands with a single resonance in the (31)P{(1)H} NMR spectrum between -95 and -97 ppm. The addition of PTA-Li to aldehydes results in a mixture of diasteromeric compounds, PTA-CHROH, with two (31)P{(1)H} NMR resonances between -100 and -106 ppm. Three (eta(6)-arene)RuCl(2)(PTA-CRR'OH) complexes of these ligands were synthesized and characterized, with the ligands binding in a kappa1 coordination mode. All the ligands and ruthenium complexes are slightly soluble in water with S25 degrees = 3.9-11.1 g/L for the PTA-CRR'OH ligands and S(25) degrees = 3.3-14.1 g/L for the (eta(6)-arene)RuCl(2)(PTA-CRR'OH) complexes.

A series of β-aminophosphines derived from 1,3,5-triaza-7-phosphaadamantane (PTA) are described. PTA-CHPhNHPh (1), PTA-CH(p-C(6)H(4)OCH(3))NHPh (2), and PTA-CPh(2)NHPh (3) were prepared in good yield (62-77%) by reaction of lithiated PTA with the corresponding imine followed by hydrolysis. Compounds 1 and 2 were synthesized as pairs of diastereomers which were separated by successive recrystallization from THF/hexane. Compounds 1-3 are somewhat soluble in water (S(25)(o) = 4.8 (1), 4.9 (2), 2.7 (3) g/L). Upon coordination to Ru(II) arene centers both monodentate (κ(1)-P) [RuCl(2)(η(6)-toluene)(1-3)] and bidentate (κ(2)-P,N) [RuCl(η(6)-toluene)(1-3)]Cl coordination modes were observed. Ru(II) arene complexes 4-6 exhibited hemilabile behavior transitioning between κ(1)-P and κ(2)-P,N coordination upon change in solvent or addition of a coordinating ligand such as Cl(-) or CH(3)CN. Complexes (4-6) were found to be active air stable catalysts for the aqueous phase hydration of various nitriles with TOF up to 285 h(-1) and TON of up to 97,000 observed.

para-CH activation of pyridine with allylbenzene is described by Ni/Al cooperative catalysis in combination with a bulkier NHC ligand and a Lewis acid, leading to linear hydroheteroarylation products. Interestingly, the branch selectivity can be achieved by using the combination of a less sterically hindered amino-NHC ligand and AlMe3 through tandem reaction of facile alkene isomerization followed by a slow CH bond activation process.