2016-39-9Relevant articles and documents
Old Concepts, New Application – Additive-Free Hydrogenation of Nitriles Catalyzed by an Air Stable Alkyl Mn(I) Complex
Weber, Stefan,Veiros, Luis F.,Kirchner, Karl
supporting information, p. 5412 - 5420 (2019/11/13)
An efficient additive-free manganese-catalyzed hydrogenation of nitriles to primary amines with molecular hydrogen is described. The pre-catalyst, a well-defined bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dpre)(CO)3(CH3)] (dpre=1,2-bis(di-n-propylphosphino)ethane), undergoes CO migratory insertion into the manganese-alkyl bond to form acyl complexes which upon hydrogenolysis yields the active coordinatively unsaturated Mn(I) hydride catalyst [Mn(dpre)(CO)2(H)]. A range of aromatic and aliphatic nitriles were efficiently and selectively converted into primary amines in good to excellent yields. The hydrogenation of nitriles proceeds at 100 °C with a catalyst loading of 2 mol % and a hydrogen pressure of 50 bar. Mechanistic insights are provided by means of DFT calculations. (Figure presented.).
Hydrogenation of Nitriles and Ketones Catalyzed by an Air-Stable Bisphosphine Mn(I) Complex
Weber, Stefan,St?ger, Berthold,Kirchner, Karl
supporting information, p. 7212 - 7215 (2018/11/25)
Efficient hydrogenations of nitriles and ketones with molecular hydrogen catalyzed by a well-defined bench-stable bisphosphine Mn(I) complex are described. These reactions are environmentally benign and atomically economic, implementing an inexpensive, earth-abundant nonprecious metal catalyst. A range of aromatic and aliphatic nitriles and ketones were efficiently converted into primary amines and alcohols, respectively, in good to excellent yields. The hydrogenation of nitriles proceeds at 100 °C with catalyst loading of 2 mol % and 20 mol % base (t-BuOK), while the hydrogenation of ketones takes place already at 50 °C, with a catalyst loading of 1 mol % and 5 mol % of base. In both cases, a hydrogen pressure of 50 bar was applied.
Reduction of aromatic and aliphatic nitro groups to anilines and amines with hypophosphites associated with Pd/C
Baron, Marc,Metay, Estelle,Lemaire, Marc,Popowycz, Florence
, p. 1006 - 1015 (2013/07/26)
The reduction of aromatic and aliphatic nitro groups to anilines and amines is performed with good yield and selectivity in short reaction times. A mixture of sodium hypophosphite and phosphinic acid is used in the presence of a heterogeneous catalyst 2.5 mol% of Pd/C (5%) in a biphasic water/2-MeTHF system.
A catalytic version of hypervalent aryl-λ3-iodane-induced Hofmann rearrangement of primary carboxamides: Iodobenzene as an organocatalyst and m-chloroperbenzoic acid as a terminal oxidant
Miyamoto, Kazunori,Sakai, Yuuta,Goda, Shunsuke,Ochiai, Masahito
supporting information; experimental part, p. 982 - 984 (2012/02/04)
The first catalytic version of hypervalent aryl-λ3- iodane-induced Hofmann rearrangement of primary carboxamides, which probably involves in situ generation of a tetracoordinated bis(aqua)(hydroxy)phenyl- λ3-iodane complex as an active oxidant from a catalytic amount of iodobenzene by the reaction with m-chloroperbenzoic acid in the presence of HBF4 in dichloromethane-water under mild conditions, was developed.
Protecting-group-free synthesis of amines: Synthesis of primary amines from aldehydes via reductive amination
Dangerfield, Emma M.,Plunkett, Catherine H.,Win-Mason, Anna L.,Stocker, Bridget L.,Timmer, Mattie S. M.
experimental part, p. 5470 - 5477 (2010/11/16)
New methodology for the protecting-group-free synthesis of primary amines is presented. By optimizing the metal hydride/ammonia mediated reductive amination of aldehydes and hemiacetals, primary amines were selectively prepared with no or minimal formation of the usual secondary and tertiary amine byproduct. The methodology was performed on a range of functionalized aldehyde substrates, including in situ formed aldehydes from a Vasella reaction. These reductive amination conditions provide a valuable synthetic tool for the selective production of primary amines in fewer steps, in good yields, and without the use of protecting groups.
