Kinetics and mechanism of the aminolysis of ethyl aryl carbonates in acetonitrile
作者:Han Joong Koh、Ji-Won Lee、Hai Whang Lee、Ikchoon Lee
DOI:10.1139/v98-038
日期:1998.6.1
The aminolysis reactions of ethyl arylcarbonates with benzylamines in acetonitrile at 25.0°C are investigated. The base-catalyzed path, k2, disappears when strong nucleophiles (X = p-CH3O and p-CH...
The direct reductive amination of electron-deficient amines with aldehydes: the unique reactivity of the Re2O7 catalyst
作者:Braja Gopal Das、Prasanta Ghorai
DOI:10.1039/c2cc33185c
日期:——
An unprecedented direct reductive amination of electron-deficient amines such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, Ar2PO-, etc. protected amines with aldehydes is achieved using the Re2O7 catalyst and silanes as the hydride source. Excellent regioselective mono-alkylation and chemoselective reductive-amination were observed.
Reactions of Cyclopropanone Acetals with Alkyl Azides: Carbonyl Addition versus Ring-Opening Pathways
作者:Scott Grecian、Pankaj Desai、Craig Mossman、Jennifer L. Poutsma、Jeffrey Aubé
DOI:10.1021/jo0711034
日期:2007.12.1
bond cleavage of the corresponding cyclopropanone, giving oxyallyl cations that were captured by azides. Aryl-substituted cyclopropanone acetals, when subjected to these conditions, afforded [1,2,3]oxaborazoles exclusively, which were also the result of C2−C3 bond rupture, azide capture, and then loss of nitrogen. In the reactions of n-hexyl-substituted cyclopropanone acetals with alkyl azides, a mixture
The aminolysis of O-methyl S-aryl thiocarbonates with benzylamines are studied in acetonitrile at −45.0 C. The βX (βnuc) values are in the range 0.62-0.80 with a negative cross-interaction constant, ρXZ = −0.42, which are interpreted to indicate a concerted mechanism. The kinetic isotope effects involving deuterated benzylamine nucleophiles (XC6H4CH2ND2) are large, kH/kD = 1.29-1.75, suggesting that
Asymmetric Dieckmann Condensation via Memory of Chirality: Synthesis of the Key Intermediate for AS-3201, an Aldose Reductase Inhibitor
作者:Takeo Kawabata、Toshihide Watanabe
DOI:10.3987/com-08-s(n)126
日期:——
Asymmetric Dieckmanncondensationvia memory of chirality has been developed. A key intermediate for the synthesis of AS-3201, an aldose reductase inhibitor, has been prepared in 94% ee by asymmetric Dieckmanncondensation of 8 derived from L-aspartic acid.