Sarkar, Koushik; Das, Kuhali; Kundu, Abhishek; Adhikari, Debashis; Maji, Biplab published their research in ACS Catalysis in 2021. The article was titled 《Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane》.Formula: C5BrMnO5 The article contains the following contents:
The synthesis of primary amines RCH2NH2HCl [R = Ph, 2-phenylethyl, (1-oxo-1,3-dihydro-2-benzofuran-5-yl)methyl, etc.], 2,2′-(1,4-phenylene)bis(ethan-1-aminium) chloride, hexane-1,6-diaminium chloride sym. and unsym. secondary amines RCH2NHCH2R and RCH2NHR1 (R1 = pyridin-2-ylmethyl, cyclohexyl, n-Bu, etc.) by hydrogenation of nitriles RCN, 1,4-benzenediacetonitrile and hexanedinitrile, employing a borrowing hydrogenation strategy was reported. A class of phosphine-free manganese (I) complexes I [R2 = thiophen-2-yl, [2-(methylsulfanyl)phenyl]methyl, (2-methoxyphenyl)methyl, furan-2-yl] bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and sym. and asym. secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle. The experimental process involved the reaction of Bromopentacarbonylmanganese(I)(cas: 14516-54-2Formula: C5BrMnO5)
Bromopentacarbonylmanganese(I)(cas: 14516-54-2) has many other uses. It is used in the formation of (eta6-arene)tricarbonylmanganese(I) by reacting with arene (arene= hexamethyl benzene, 1,2,4,5-tetramethyl benzene, mesitylene, p-xylene and toluene) in the presence silver salt.Formula: C5BrMnO5
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary