1416448-63-9Relevant academic research and scientific papers
Chiral Arylated Amines via C?N Coupling of Chiral Amines with Aryl Bromides Promoted by Light
Cao, Rui,Li, Jing-Sheng,Song, Geyang,Tang, Wei-Jun,Wang, Chao,Xiao, Jianliang,Xue, Dong,Yang, Liu,Zhang, Wei
, p. 21536 - 21542 (2021)
The Buchwald-Hartwig C-N coupling reaction has found widespread applications in organic synthesis. Over the past two decades or so, many improved catalysts have been introduced, allowing various amines and aryl electrophiles to be readily used nowadays. However, there lacks a protocol that could be used to couple a wide range of chiral amines and aryl halides, without erosion of the enantiomeric excess (ee). Reported in this article is a method based on molecular Ni catalysis driven by light, which enables stereoretentive C-N coupling of optically active amines, amino alcohols, and amino acid esters with aryl bromides, with no need for any external photosensitizer. The method is effective for a wide variety of coupling partners, including those bearing functional groups sensitive to bases and nucleophiles, thus providing a viable alternative to accessing synthetically important chiral N-aryl amines, amino alcohols, and amino acids esters. Its viability is demonstrated by 92 examples with up to 99 % ee.
Asymmetric hydrogenation of N-arylimines catalyzed by the xyl-skewphos/DPEN-ruthenium(II) complex
Arai, Noriyoshi,Utsumi, Noriyuki,Matsumoto, Yuki,Murata, Kunihiko,Tsutsumi, Kunihiko,Ohkuma, Takeshi
supporting information, p. 2089 - 2095 (2012/11/07)
The new catalyst system of RuBr2[(S,S)-xyl-skewphos][(S,S)-dpen] and potassium tert-butoxide shows high reactivity and enantioselectivity in the hydrogenation of N-arylimines [Xyl-Skewphos=2,4-bis(di-3,5-xylylphosphino) pentane, DPEN=1,2-diphenylethylenediamine]. A range of imines derived from aromatic and heteroaromatic ketones as well as some ferrocenyl and vinylic imines are hydrogenated with a turnover number as high as 18,000 under 10-50 atm of hydrogen to afford the amine products in up to 99% enantiomeric excess. The reaction is applied to the synthesis of a chiral N-arylamine, which is the synthetic intermediate of a biologically active compound. The mode of enantioselection is interpreted by using transition-state models based on the X-ray structure of the Xyl-Skewphos/DPEN-RuBr2 complex. Copyright
