Design, Preparation, X-ray Crystal Structure, and Reactivity of <i>o</i>-Alkoxyphenyliodonium Bis(methoxycarbonyl)methanide, a Highly Soluble Carbene Precursor
作者:Chenjie Zhu、Akira Yoshimura、Lei Ji、Yunyang Wei、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1021/ol301268j
日期:2012.6.15
The preparation, X-ray structure, and reactivity of new, highly soluble, and reactive iodonium ylides derived from malonate methyl ester and bearing an ortho substituent on the phenyl ring are reported. These new reagents show higher reactivity than common phenyliodonium ylides in the Rh-catalyzed cyclopropanation, C–H insertion, and transylidation reactions under homogeneous conditions.
Benzo[b]thiophenium S,C-ylides: Preparation, structure and comparison with thiophenium analogues
作者:Eino Vuorinen、Anthony A. Chalmers、Jan L.M. Dillen、Tomasz A. Modro
DOI:10.1016/s0040-4020(01)82404-2
日期:1991.9
13C) studies revealed that ylides substituted additionally at position 2 of the thiophene ring can exist as pairs of diastereoisomers, not interchangeable at room temperature. The slow exchange between two sites was attributed to the restricted rotation about the ylidic SC bond. The crystalstructure determined for one ylide demonstrated different molecular environment for two parts of the β-dicarbonyl
Modulation of Carbene Spin State Population through Precursor Photophysics
作者:William S. Jenks、Melanie J. Heying、Erin M. Rockafellow
DOI:10.1021/ol802934w
日期:2009.2.19
Dicarbomethoxycarbene can be generated by photolysis of S-C sulfonium ylides derived from thiophene. By manipulating the thiophene (leaving group) portion of the ylide, the initial spin distribution of the carbenes can be strongly influenced, With certain carbene traps, product distributions from dicarbomethoxycarbene depend on the initial spin state distribution in which the carbene is generated and this is used as a means to report on the initial spin state distributions. This approach should be general for other carbenes generated from analogous precursors.
Reaction of Dicarbomethoxycarbene with Thiophene Derivatives
作者:William S. Jenks、Melanie J. Heying、Stacey A. Stoffregen、Erin M. Rockafellow
DOI:10.1021/jo802823s
日期:2009.4.3
Photolysis of derivatives of dimethylmalonate thiophene-S,C-ylide provides dicarbomethoxycarbene, which can react with thiophene to form dimethyl (2-thienyl)malonate. By generation of dicarbomethoxycarbene from the dibenzothiophene-based ylide in neat thiophene, it is shown that the thienylmalonate is not a product of rearrangement of the thiophene ylide, in contrast to thermolysis results. Formation
<i>S,C</i>-Sulfonium Ylides from Thiophenes: Potential Carbene Precursors
作者:Stacey A. Stoffregen、Melanie Heying、William S. Jenks
DOI:10.1021/ja076351w
日期:2007.12.1
Photolysis of S,C-sulfonium ylides derived from thioanisol, thiophene, benzothiophene, or dibenzothiophene provides products deriving from dicarbomethoxycarbene. In methanol, no rearrangement of the carbene to the ketene derivative is observed. Formation of dibenzothiophene and benzothiophene is quantitative. For the thiophene-based ylide, insertion of the carbene into the alpha-CH bond of thiophene