53053-99-9Relevant articles and documents
Tunable Ligand Effects on Ruthenium Catalyst Activity for Selectively Preparing Imines or Amides by Dehydrogenative Coupling Reactions of Alcohols and Amines
Higuchi, Takafumi,Tagawa, Risa,Iimuro, Atsuhiro,Akiyama, Shoko,Nagae, Haruki,Mashima, Kazushi
, p. 12795 - 12804 (2017/09/06)
Selective dehydrogenative synthesis of imines from a variety of alcohols and amines was developed by using the ruthenium complex [RuCl2(dppea)2] (6 a: dppea=2-diphenylphosphino-ethylamine) in the presence of catalytic amounts of Zn(OCOCF3)2 and KOtBu, whereas the selective dehydrogenative formation of amides from the same sources was achieved by using another ruthenium complex, [RuCl2{(S)-dppmp}2] [6 d: (S)-dppmp=(S)-2-((diphenylphosphenyl)methyl)pyrrolidine], in the presence of catalytic amounts of Zn(OCOCF3)2 and potassium bis(trimethylsilyl)amide (KHMDS). Our previously reported ruthenium complex, [Ru(OCOCF3)2(dppea)2] (8 a), was the catalyst precursor for the imine synthesis, whereas [Ru(OCOCF3)2{(S)-dppmp}2] (8 d), which was derived from the treatment of 6 d with Zn(OCOCF3)2 and characterized by single-crystal X-ray analysis, was the pre-catalyst for the amide formation. Control experiments revealed that the zinc salt functioned as a reagent for replacing chloride anions with trifluoroacetate anions. Plausible mechanisms for both selective dehydrogenative coupling reactions are proposed based on a time-course study, Hammett plot, and deuterium-labeling experiments.
A metalloenzyme-like catalytic system for the chemoselective oxidative cross-coupling of primary amines to imines under ambient conditions
Largeron, Martine,Fleury, Maurice-Bernard
, p. 3815 - 3820 (2015/03/04)
The direct oxidative cross-coupling of primary amines is a challenging transformation as homocoupling is usually preferred. We report herein the chemoselective preparation of cross-coupled imines through the synergistic combination of low loadings of CuII metal-catalyst and o-iminoquinone organocatalyst under ambient conditions. This homogeneous cooperative catalytic system has been inspired by the reaction of copper amine oxidases, a family of metalloenzymes with quinone organic cofactors that mediate the selective oxidation of primary amines to aldehydes. After optimization, the desired cross-coupled imines are obtained in high yields with broad substrate scope through a transamination process that leads to the homocoupled imine intermediate, followed by dynamic transimination. The ability to carry out the reactions at room temperature and with ambient air, rather than molecular oxygen as the oxidant, and equimolar amounts of each coupling partner is particularly attractive from an environmentally viewpoint.
Catalytic coupling of nitriles with amines to selectively form imines under mild hydrogen pressure
Srimani, Dipankar,Feller, Moran,Ben-David, Yehoshoa,Milstein, David
supporting information, p. 11853 - 11855 (2013/01/16)
Imines are selectively formed by coupling of nitriles and amines under mild hydrogen pressure. The reaction is catalyzed by a bipyridine-based PNN Ru(ii) pincer complex and proceeds under mild, neutral conditions at 4 bar of H 2.
