Stereoselective Syntheses of Epothilones A and B via Nitrile Oxide Cycloadditions and Related Studies
作者:Jeffrey W. Bode、Erick M. Carreira
DOI:10.1021/jo015791h
日期:2001.9.1
epothilones A and B are described. The routes described make extensive study of nitrileoxide cycloadditions as surrogates for aldoladdition reactions and have led to the realization of a highly convergent synthesis based on the Kanemasa hydroxyl-directed nitrileoxide cycloaddition. As well, our synthetic efforts have led to the development of new reaction methodologies and served as the proving ground for
Tris(trimethylsilyl)sulfonium and Methylbis(trimethylsilyl)sulfonium Ions: Preparation, NMR Spectroscopy, and Theoretical Studies<sup>1</sup>
作者:G. K. Surya Prakash、Chulsung Bae、Qunjie Wang、Golam Rasul、George A. Olah
DOI:10.1021/jo001248+
日期:2000.11.1
Tris(trimethylsilyl)sulfonium 1 and methylbis(trimethylsilyl)sulfonium 2 ions were prepared as long-lived species by reacting trimethylsilane and trityl tetrakis(pentafluorophenyl)borate (Ph(3)C(+) TPFPB) in the presence of precursor sulfides and characterized by (1)H, (13)C, and (29)Si NMR spectroscopy at -78 degrees C. Attempted preparation of dimethyl(trimethylsilyl)sulfonium ion under similar conditions
Reductive Elimination from Platinum(IV) Aminotroponiminate Dimethyl Complexes Promoted by Sterically Hindered Lewis Bases
作者:Elise Traversa、Joseph L. Templeton、Hiu Yan Cheng、Megan Mohadjer Beromi、Peter S. White、Nathan M. West
DOI:10.1021/om400034y
日期:2013.3.25
form [(ATI)Pt(CH3)2(CNR)(SMe2)][OTf] (4). Complex 3 also undergoes ligand substitution reactions with azide or cyanide to form (ATI)Pt(CH3)2(N3)(SMe2) (5a) or (ATI)Pt(CH3)2(CN)(SMe2) (5b). Addition of PR3 results in the substitution product [(ATI)Pt(CH3)2(PR3)(SMe2)][OTf] for phosphines with cone angles ≤136° (P(OMe)3, PMe3, PMe2Ph). The PtIV complex [(ATI)Pt(CH3)2(PPh2Me)(SMe2)][OTf] (6c) reductively
Solvent Effects on Methyl Transfer Reactions. 2. The Reaction of Amines with Trimethylsulfonium Salts
作者:Henry Castejon、Kenneth B. Wiberg、Stepan Sklenak、Wolfgang Hinz
DOI:10.1021/ja0042940
日期:2001.6.1
yielding a reaction path very similar to that in gas phase but with significant differences in the relative energy of the critical points. In DMSO, the energy profile is greatly simplified by the disappearance of several of the species found in gas phase and in cyclohexane. The activation free energy increases with the polarity of the solvent in both reactions. Increasing the polarity of the solvent also
Revisiting the Corey–Chaykovsky reaction: the solvent effect and the formation of β-hydroxy methylthioethers
作者:Yu Peng、Jin-Hui Yang、Wei-Dong Z. Li
DOI:10.1016/j.tet.2005.10.068
日期:2006.2
The classical Corey-Chaykovsky (CC) reaction of ketones in ethereal solvents (i.e., THF or Et2O) resulted in the production of a 14 significant amount of P-hydroxy methylthioether 2 along with normal epoxide product 1. Some interesting and synthetically useful transformations of the CC reaction product of cyclopropyl ketones were also described. (c) 2005 Elsevier Ltd. All rights reserved.