Synthesis of Vinyl-Functionalized Oxazoles by Olefin Cross-Metathesis
作者:Thomas J. Hoffman、James H. Rigby、Stellios Arseniyadis、Janine Cossy
DOI:10.1021/jo702305g
日期:2008.3.1
A ruthenium-based catalyzed olefin cross-methathesis reaction involving 2- and 4-vinyl-functionalized oxazoles was developed. A wide range of olefinic partners was coupled in good to excellent yields and high stereoselectivities under mild conditions. This methodology offers new opportunities for the synthesis of a plethora of biologically active natural products.
Catalytic, Enantioselective N-Acylation of Lactams and Thiolactams Using Amidine-Based Catalysts
作者:Xing Yang、Valentina D. Bumbu、Peng Liu、Ximin Li、Hui Jiang、Eric W. Uffman、Lei Guo、Wei Zhang、Xuntian Jiang、K. N. Houk、Vladimir B. Birman
DOI:10.1021/ja306766n
日期:2012.10.24
contrast to alcohols and amines, racemic lactams and thiolactams cannot be resolved directly via enzymatic acylation or classical resolution. Asymmetric N-acylation promoted by amidine-based catalysts, particularly Cl-PIQ 2 and BTM 3, provides a convenient method for the kinetic resolution of these valuable compounds and often achieves excellent levels of enantioselectivity in this process. Density
Substrate acidities and conversion times for reactions of amides with di-tert-butyl bicarbonate
作者:Marvin M. Hansen、Allen R. Harkness、D. Scott Coffey、Frederick G. Bordwell、Yongyu Zhao
DOI:10.1016/0040-4039(95)01931-7
日期:1995.12
The conversion time tor 4-dimethylaminopyndine catalysed reaction of amides with di-tert-butyl dicarbonate varies dramatically with substrateacidity. The pKa's in DMSO of some amides are determined to support correlation of reactivity with substrateacidity. Particularly acidic substrates, such as 4-thiazolidinone, readily react with a variety of dialkyl dicarbonates. Less acidic substrates react
Compounds that modulate the oxidoreductase enzyme indoleamine 2,3-dioxygenase, and compositions containing the compounds, are described herein. The use of such compounds and compositions for the treatment and/or prevention of a diverse array of diseases, disorders and conditions, including cancer- and immune-related disorders, that are mediated by indoleamine 2,3-dioxygenase is also provided.