Hydrogen-deuterium exchange of the anionic Group VIB transition-metal hydrides. Convenient, in situ deuterium transfer reagents

Hydride Exchange Processes in the Coordination Sphere of Transition Metal Complexes: The OsH3(BH4)(PR3)2 System

“…The main problem for the characterization of these dynamic phenomena is precisely their great diversity. , There are the formally simplest examples where two nonequivalent hydride ligands exchange their positions, like [OsH 2 (CO)(NO)(PR 3 ) 2 ] + , Re(CO)H 2 (PR 3 ) 2 (NO), and MH 2 (PR 3 ) 4 (M = Fe, Ru). , There are cases where the hydride ligand exchanges with another hydrogen atom not originally attached to the metal, being it from a thiol group of another ligand in [IrH 2 (HS(CH 2 ) 3 SH)(PCy 3 ) 2 ] + , or an acidic proton present in the solvent in [HM(CO) 4 L] - (M = Cr, Mo, W; L = CO, PR 3 ) and Re(CO)H 2 (NO)L 2 , these latter processes going very likely through weakly bound complex−solvent species. There is finally the wealth of exchange processes associated with bridging hydrogen atoms, especially with BH 4 and derivatives ((C 5 H 5 ) 2 V(BH 4 ),18a (C 5 H 5 ) 2 Ta(PMe 3 )(H 3 BSi( t Bu) 2 H),18b [Mo(CO) 4 (BH 4 )] - ,18c (C 5 H 5 )ZrH(BH 4 ), OsH 3 (BH 4 )(P(c-C 5 H 9 ) 3 ) 2 20 ), but not limited to them (RhH((μH)SnR 3 ) 2 (PPh 3 ) 2 21 ).…”

Molybdenum and Tungsten Catalysts for Hydrogenation, Hydrosilylation and Hydrolysis

“…An advantage is that in many cases further reduction of the aldehyde to alcohols, which is a problem with some borohydride reagents, is avoided with these metal hydrides. The hydride in (CO) 5 CrH − or (CO) 5 WH − readily exchanges with deuterated alcohols, so use of the hydride in the presence of CH 3 OD provides a means of converting acyl chlorides or alkyl halides to deuterated products, as shown in Equation 3.5 [29] .…”

Pentacarbonylhydridochromates M+[HCr(CO)5]−: Reactivity in Organic Synthesis and Homogeneous Catalysis

“…Indeed, taking advantage of the facile H/D exchange with CH 3 OD of the [PPN] ϩ salt, Equation (21), the reduction of benzoyl chloride with the reagent prepared in situ from [PPN] ϩ [HCr(CO) 5 ] Ϫ and CH 3 OD (2-fold molar excess) in THF affords PhCDO [Equation (22)]. [46] (21) (22) …”

“…[72Ϫ76] However, Darensbourg et al presented compelling evidence that the initial mechanistic step in the thermal WGSR by Group 6B carbonylmetal compounds is in fact transition metal activation of CO towards attack by hydroxide ions [Equation (46)]. [29][74] (46) Once the active [HCr(CO) 5 ] Ϫ is formed, the formato complex [HCO 2 Cr(CO) 5 ] Ϫ could then be generated according to Equation (43), (44), and (41).…”