1215863-53-8Relevant articles and documents
Metal-Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles
Pirola, Margherita,Faverio, Chiara,Orlandi, Manuel,Benaglia, Maurizio
supporting information, p. 10247 - 10250 (2021/06/18)
A metal-free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β-substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α-functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β-cyano esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
Rhodium-catalyzed asymmetric hydrogenation of β-cyanocinnamic esters with the assistance of a single hydrogen bond in a precise position
Li, Xiuxiu,You, Cai,Yang, Yusheng,Yang, Yuhong,Li, Pan,Gu, Guoxian,Chung, Lung Wa,Lv, Hui,Zhang, Xumu
, p. 1919 - 1924 (2018/02/23)
With the assistance of hydrogen bonds, the first asymmetric hydrogenation of β-cyanocinnamic esters is developed, affording chiral β-cyano esters with excellent enantioselectivities (up to 99% ee). This novel methodology provides an efficient and concise synthetic route to chiral GABA-derivatives such as (S)-Pregabalin, (R)-Phenibut, (R)-Baclofen. Interestingly, in this system, the catalyst with a single H-bond donor performs better than that with double H-bond donors, which is a novel discovery in the metalorganocatalysis area.
Catalytic asymmetric synthesis of secondary nitriles via stereoconvergent negishi arylations and alkenylations of racemic α-bromonitriles
Choi, Junwon,Fu, Gregory C.
supporting information; experimental part, p. 9102 - 9105 (2012/07/13)
The first method for the stereoconvergent cross-coupling of racemic α-halonitriles is described, specifically, nickel-catalyzed Negishi arylations and alkenylations that furnish an array of enantioenriched α-arylnitriles and allylic nitriles, respectively. Noteworthy features of this investigation include: the highly enantioselective synthesis of α-alkyl-α-aryl nitriles that bear secondary α-alkyl substituents; the first examples of the use of alkenylzinc reagents in stereoconvergent Negishi reactions of alkyl electrophiles; demonstration of the utility of a new family of ligands for asymmetric Negishi cross-couplings (a bidentate bis(oxazoline), rather than a tridentate pybox); in the case of arylzinc reagents, carbon-carbon bond formation at a remarkably low temperature (-78 °C), the lowest reported to date for an enantioselective cross-coupling of an alkyl electrophile; a mechanistic dichotomy between Negishi reactions of an unactivated versus an activated secondary alkyl bromide.
