17972-08-6Relevant articles and documents
Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron
Chen, Dongping,Li, Kaidi,Tang, Wenjun,Xu, Guangqing,Xu, Ronghua,Zhou, Mingkang
supporting information, p. 10337 - 10342 (2020/07/04)
We herein report a general, practical, and highly efficient method for asymmetric synthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method signifies the generality of diboron-enabled [3,3]-sigmatropic rearrangement.
Mechanosynthesis of N-methyl imines using recyclable imidazole-based acid-scavenger: In situ formed ionic liquid as catalyst and dehydrating agent
Khaligh, Nader Ghaffari,Ling, Ong Chiu,Mihankhah, Taraneh,Johan, Mohd Rafie,Ching, Juan Joon
, p. 194 - 199 (2018/12/04)
1,1′-(1,4-Butanediyl)bis(imidazole) was prepared by a modified method and its application as an efficient promoter was demonstrated for the mechanosynthesis of N-methyl imines using ball milling as a non-conventional process under solvent-free conditions. In this new protocol design, the bis-imidazole acted as a recyclable acid-scavenging agent. This efficient approach to the N-methyl imines displays a combination of the synthetic virtues of a non-conventional condensation reaction with ecological benefits and convenience of a facile mechanosynthetic process. The current method has advantages such as reduced waste by avoiding solvent, exclusion of hazardous materials during the reaction, elimination of handling an anhydrous gas in an evacuated container or a solution of methylamine in ethanol, good yields for relatively unreactive benzaldehydes containing electron-donating substituents, short reaction times, and metal- and acid-free conditions. Furthermore, the promoter was easily regenerated and reused several times with no significant loss of activity.
Synthesis of N-methyl imines in the presence of poly(N-vinylpyridine) as a reusable solid base catalyst by a mechanochemical process
Khaligh, Nader Ghaffari,Abbo, Hanna S.,Titinchi, Salam J. J.
, p. 901 - 910 (2017/02/10)
The synthesis of N-methyl imines was performed in the presence of catalytic amounts of poly(4-vinylpyridine) in high yields and rapidly at room temperature by a ball milling process. This new method has some advantages including good yields for relatively unreactive carbonyl compounds and short reaction times as well as being green in terms of avoiding the use of toxic reagents and solvents. The major advantage of this process is that the catalyst can be easily regenerated and reused several times without any significant loss of activity.
