نتایج جستجو برای: trimethylsilyl cyanide
تعداد نتایج: 10439 فیلتر نتایج به سال:
Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate
Propylene carbonate can be used as a green solvent for the asymmetric synthesis of cyanohydrin trimethylsilyl ethers from aldehydes and trimethylsilyl cyanide catalysed by VO(salen)NCS, though reactions are slower in this solvent than the corresponding reactions carried out in dichloromethane. A mechanistic study has been undertaken, comparing the catalytic activity of VO(salen)NCS in propylene...
A new procedure is described for the synthesis of a,/?-glycosyl cyanides by the reaction of per-O-benzylated S-a-D-glycopyranosyl phosphorothioates with trimethylsilyl cyanide in the presence of Lewis acid. Starting S-glycosyl phosphorothioates are prepared, directly, from O-benzyl protected reducing D-hexopyranoses (gluco-, galacto-, manno-) and alkylammonium salt of phosphorothioic acid under...
We have demonstrated that a cooperative catalytic system comprised of CuCl and Cu(OTf)(2) could be used to effectively catalyse the three-, five- and seven-component coupling reactions of aliphatic or aromatic amines, formaldehyde, and trimethylsilyl cyanide (TMSCN), and selectively produce in good yields the corresponding cyanomethylamines, N,N-bis(cyanomethyl)amines and N,N'-bis(cyanomethyl)m...
The chiral oxazaborolidinium salts 1 and 2 are excellent catalysts for the enantioselective cyanosilylation of a wide variety of aldehydes (see Table 1) using trimethylsilyl (TMS) cyanide and triphenylphosphine oxide as the source of a new reactive cyanide donor. This donor appears to be the isocyanophosphorane Ph3P(OTMS)(N=C:) (4). The novel process described herein has several advantages: pre...
The enantioselective organocatalytic Strecker-type reaction of aliphatic N,N-dialkylhydrazones is presented. Using trimethylsilyl cyanide (TMSCN) as the cyanide source, the reaction can be efficiently catalyzed by a tert-leucine-derived bifunctional thiourea to afford the corresponding hydrazino nitriles in good to excellent yields (50-96%) and moderate to good enantioselectivities, up to 86% e...
A simple and efficient one-pot, three-component Strecker reaction of protected amino acids, aromatic aldehydes, and trimethylsilyl cyanide has been developed for the synthesis of chiral α-amino nitriles. The reaction was carried out in the presence of catalytic amount of phosphotungstic acid (H3[P(W3O10)4]) as an environmentally friendly cata...
A catalyst-free one-pot three component methodology for the synthesis of α-aminonitriles under ultrasonic irradiation at room temperature using [Bmim]Br as a neutral reaction medium is described. A broad range of substrates including the aromatic, heteroaromatic and aliphatic aldehydes were condensed with amines (aliphatic and aromatic) and trimethylsilyl cyanide (TMSCN). Using this method, all...
Abstract 3-Aryloxindole derivatives were synthesized through a Friedel–Crafts-type cyclization. The reaction was catalyzed by trimethylsilyl tricyanopalladate complex generated in situ from cyanide and Pd(OAc)2. Wide varieties of diethyl phosphates derived N-arylmandelamides converted almost quantitatively into oxindoles. When N,N-dibenzylamide used instead an anilide substrate, benzo-fused δ-l...
1-Ethyl-3-methylimidazolium acetate is introduced as a robust organocatalyst for solvent-free cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). The catalyst loading can be reduced to as low as 0.1-0.0001 mol % under mild reaction conditions, giving considerably high TOF values from 10,843 h-1 to 10,602,410 h-1 in the field of organocatalyzed transformations. The present...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید