A stereocontrolled approach to electrophilic epoxides
作者:Otto Meth-Cohn、Clive Moore、Heinrich C. Taljaard
DOI:10.1039/p19880002663
日期:——
Lithium t-butyl hydroperoxide (easily generated by addition of an alkyl-lithium to anhydrous t-butyl hydroperoxide in THF solution) is a powerful reagent for the epoxidation of electrophilic alkenes at –20 to 0 °C under full stereocontrol.
A powerful new stereo-controlled method for epoxidation of electrophilic alkenes
作者:Carol Clark、Patricia Hermans、Otto Meth-Cohn、Clive Moore、Heinrich C. Taljaard、Gerda van Vuuren
DOI:10.1039/c39860001378
日期:——
tetrahydrofuran are shown to epoxidise α,β-unsaturated esters and sulphones efficiently in a stereo- and regio-specific manner, while esters of chiral alcohols undergo diastereofacially selective epoxidation.
Preparation and ring-opening reactions of 2-phenylsulphonyl-2-trimethylsilyl-oxiranes
作者:Cheryl T. Hewkin、Richard F.W. Jackson
DOI:10.1016/s0040-4039(00)98809-9
日期:1990.1
trimethylsilyl oxiranes(2), which on treatment with MgBr2Et2O gave 2-bromoacylsilanes(3) and either bromovinyl sulphones(5) or α,β-unsaturated acylsilanes(6) and 2-trimethylsilyl car☐ylic acids(7), depending on structure.
在氯代三甲基硅烷存在下,2-苯基磺酰基肟基(1)与丁基锂反应生成2-苯基磺酰基-2-三甲基甲硅烷基肟基(2),经MgBr 2 Et 2 O处理后生成2-溴酰基硅烷(3)和两种溴化砜基( 5)或α,β-不饱和酰基硅烷(6)和2-三甲基甲硅烷基羧基丙烯酸(7),具体取决于结构。
Phenylsulphonyl oxirane: a versatile reagent for organic synthesis
作者:Mark Ashwell、Richard F. W. Jackson
DOI:10.1039/c39880000645
日期:——
Phenylsulphonyloxirane (1) reacts as the synthetic equivalent of the acetaldehyde dipolar synthon (2).
Design, Synthesis, and Evaluation of 2-(arylsulfonyl)oxiranes as Cell-permeable Covalent Inhibitors of Protein Tyrosine Phosphatases
作者:Dibyendu Dana、Tirtha K. Das、Ish Kumar、Anibal R. Davalos、Kevin J. Mark、Daryl Ramai、Emmanuel J. Chang、Tanaji T. Talele、Sanjai Kumar
DOI:10.1111/j.1747-0285.2012.01437.x
日期:2012.10
A structure‐based design approach has been applied to develop 2‐(arylsulfonyl)oxiranes as potential covalent inhibitors of protein tyrosine phosphatases. A detailed kinetic analysis of inactivation by these covalent inhibitors reveals that this class of compounds inhibits a panel of protein tyrosine phosphatases in a time‐ and dose‐dependent manner, consistent with the covalent modification of the enzyme active site. An inactivation experiment in the presence of sodium arsenate, a known competitive inhibitor of protein tyrosine phosphatase, indicated that these inhibitors were active site bound. This finding is consistent with the mass spectrometric analysis of the covalently modified protein tyrosine phosphatase enzyme. Additional experiments indicated that these compounds remained inert toward other classes of arylphosphate‐hydrolyzing enzymes, and alkaline and acid phosphatases. Cell‐based experiments with human A549 lung cancer cell lines indicated that 2‐(phenylsulfonyl)oxirane (1) caused an increase in intracellular pTyr levels in a dose‐dependent manner thereby suggesting its cell‐permeable nature. Taken together, the newly identified 2‐(arylsulfonyl)oxiranyl moiety could serve as a novel chemotype for the development of activity‐based probes and therapeutic agents against protein tyrosine phosphatase superfamily of enzymes.