119718-88-6Relevant articles and documents
Preparation of optically active cyanohydrins using the (S)-hydroxynitrile lyase from Hevea brasiliensis
Schmidt, Michael,Herve, Stephanie,Klempier, Norbert,Griengl, Herfried
, p. 7833 - 7840 (1996)
Several aliphatic, aromatic and heteroaromatic aldehydes have been converted into the chiral cyanohydrins using the (S) hydroxynitrile lyase from Hevea brasiliensis. The corresponding cyanohydrins were obtained in moderate to good yield and high enantiomeric excess with the exeption of phenyloxyacetaldehyde, benzyloxyacetaldehyde and the pyrrole-, pyridine- and indolealdehydes investigated. In contrast to previously reported results, cinnamaldehyde could be converted into (S)-(-)-2-hydroxy-4-phenyl-(E)-but-3- enenitrile with good selectivity by means of optimized reaction conditions.
Optimisation of the enantioselective synthesis of cyanohydrin esters
Veum, Lars,Kanerva, Liisa T.,Halling, Peter J.,Maschmeyer, Thomas,Hanefeld, Ulf
, p. 1015 - 1021 (2005)
The base- and lipase-catalysed enantioselective synthesis of cyanohydrin esters was investigated, and the problem of previously reported low yields due to residual water in the reaction mixture was addressed. When the lipase was immobilised on Celite R-633 as a carrier, both the enantioselectivity and the reaction times for this dynamic kinetic resolution were improved, thus enabling a highly enantioselective synthesis of aromatic and heteroaromatic cyanohydrin acetates.
A bimetallic aluminium(salen) complex for asymmetric cyanohydrin synthesis
North, Michael,Williamson, Courtney
, p. 3249 - 3252 (2009)
In the presence of a phosphine oxide cocatalyst, a bimetallic aluminium(salen) complex was found to catalyse the asymmetric addition of trimethylsilyl cyanide to aldehydes. Under optimised conditions, enantioselectivities of 53-96% were obtained using 2 m
Catalytic, asymmetric synthesis of α-acetoxy amides
North, Michael,Parkins, Adrian W.,Shariff, Atiya N.
, p. 7625 - 7627 (2004)
Treatment of aldehydes with a titanium (salen) based catalyst, potassium cyanide and acetic anhydride gives non-racemic cyanohydrin acetates, which undergo chemoselective hydrolysis to α-acetoxy amides when treated with a platinum phosphinito catalyst.
Lipase-catalyzed dynamic kinetic resolution giving optically active cyanohydrins: use of silica-supported ammonium hydroxide and porous ceramic-immobilized lipase
Sakai, Takashi,Wang, Kefei,Ema, Tadashi
, p. 2178 - 2183 (2008)
Synthetically useful cyanohydrin acetates, ArCH(OAc)CN (Ar=C6H5, 3,4-methylenedioxyphenyl, 4-Me-C6H4, 4-Cl-C6H4, 4-F-C6H4, 4-CF3-C6H4), were successfully synthesized in high enantiomeric purities (79-93% ee) via the lipase-catalyzed dynamic kinetic resolution (DKR) of cyanohydrins synthesized in situ from the corresponding aldehydes and acetone cyanohydrin. The combined use of silica-supported BTAH (benzyltrimethylammonium hydroxide) and porous ceramic-immobilized lipase under the optimized reaction conditions enabled the remarkable acceleration of the enantioselective DKR reactions.
Mechanistic comparison of aluminium based catalysts for asymmetric cyanohydrin synthesis
North, Michael,Villuendas, Pedro,Williamson, Courtney
, p. 1915 - 1924 (2010)
A kinetic analysis of the asymmetric addition of trimethylsilyl cyanide to benzaldehyde using three aluminium based catalysts has been carried out. All three catalysts displayed rate equations, which were first order in trimethylsilyl cyanide concentratio
Asymmetric Cyanosilylation of Aldehydes by a Lewis Acid/Base Synergistic Catalyst of Chiral Metal Clusters
Huang, Kai-Xin,Kong, Xiang-Jian,Li, Jun-Ping,Long, La-Sheng,Weng, Zhen-Zhang,Xie, Jing,Zheng, Lan-Sun
, p. 4121 - 4129 (2022/03/09)
Metal clusters with well-defined crystal structures are extremely useful for studying the synergistic catalytic effects and associated catalytic mechanisms. In this study, two pairs of chiral lanthanide-transition metal clusters (R)/(S)-Co3Ln2(Ln = Tb or Dy) were synthesized using Schiff-base ligands [(R)- or (S)-H3L] with multiple Lewis base sites (O sites). The as-prepared (R)/(S)-Co3Ln2chiral metal clusters exhibited good catalytic functionality in the asymmetric synthesis of chiral cyanohydrins, with high conversions of up to 99% and medium-to-high enantiomeric excess values of up to 78%. The catalysis process followed a mechanism in which the bifunctional metal clusters of (R)/(S)-Co3Ln2, containing Lewis acid sites and Lewis base sites, simultaneously activated the aldehydes and trimethylsilyl cyanide, respectively. Consequently, synergistic catalysis was realized. The enantioselectivity of the different aldehydes and stereochemical configuration of the resulting products are attributed to the formation of a steric chiral pocket via the external chiral ligands on the clusters. In addition, heterogeneous asymmetric cyanosilylation using (R)/(S)-Co3Ln2chiral metal clusters achieved high chemoselectivity and regioselectivity under mild conditions.
Palladium-catalyzed C-H activation of simple arenes and cascade reaction with nitriles: access to 2,4,5-trisubstituted oxazoles
Dai, Ling,Yu, Shuling,Shao, Yinlin,Li, Renhao,Chen, Zhongyan,Lv, Ningning,Chen, Jiuxi
supporting information, p. 1376 - 1379 (2021/02/22)
An efficient and straightforward protocol for the assembly of the pharmaceutically and biologically valuable oxazole skeleton is achieved for the first time from readily available simple arenes and functionalized aliphatic nitriles. This transformation in
Divergent Palladium-Catalyzed Tandem Reaction of Cyanomethyl Benzoates with Arylboronic Acids: Synthesis of Oxazoles and Isocoumarins
Chen, Jiuxi,Chen, Zhongyan,Dai, Ling,Shao, Yinlin,Xiong, Wenzhang,Xu, Tong,Yu, Shuling
supporting information, (2020/04/15)
A palladium-catalyzed tandem reaction of cyanomethyl benzoates with arylboronic acids has been achieved. Substitution at the 2-position of cyanomethyl benzoates was found to be crucial for the selective synthesis of oxazoles and isocoumarins. Cyanomethyl
