Reactivity of Substituted Phenyldimethylsulfonium Ions with Common Nucleophiles. A Test of pKlgMe for Phenyldimethylsulfonium Salts and a Comparison with Methyl Arenesulfonates
摘要:
The correlations of nucleophilic rate data for phenyldimethylsulfonium ions with common nucleophiles with pK(lg)(Me) values shows that the slopes of the line, beta(lg)(Me), correlate qualitatively with Edwards hardness parameter for the nucleophile, and not with the Swain-Scott n(o) parameter. Comparison with substituted methyl arenesulfonates shows different leaving group behavior in the two systems. These results support Shaik's hypothesis that leaving group behavior consists of some SET character.
Ring Enlargement Reaction of C,N-Cyclic-N′-acyl Azomethine Imines with Sulfonium Ylide: An Efficient Synthesis of 3-Benzazepine Derivatives
摘要:
Highly efficient formation of 3-benzazepine derivatives has been achieved, based on the ring expansion reaction of C,N-cyclic-N'-acyl azomethine imines with sulfonium ylide generated in situ from the corresponding sulfonium salt. The reactions proceeded smoothly to afford the tricyclic 3-benzazepine derivatives in good to high yields. A wide range of C,N-cyclic N'-acyl azomethine imines were applicable to this reaction.
1-Alkynyl(phenyl)-lambda 3-iodanes undergo selective transfer of the alkynyl groups over the phenylgroup onto diphenyl chalcogens. Exposure of 1-alkynyl(phenyl)-lambda 3-iodanes to diphenyl chalcogens (S, Se, and Te) in dichloromethane or 1,2-dichloroethane affords 1-alkynyl(diphenyl)sulfonium, -selenonium, and -telluronium salts in high yields.
The use of sulfur ylides in the synthesis of 3-alkyl(aryl)thio-4-trifluoromethylpyrroles from mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates
作者:Ryosuke Saijo、Masami Kawase
DOI:10.1016/j.tetlet.2012.03.130
日期:2012.5
In this report, we describe a new method for the synthesis of densely functionalized pyrroles. Reaction of mesoionic 1,3-oxazolium-5-olates with various S-ylides proceeds via nucleophilic addition followed by opening of the oxazole ring and subsequent cyclization to multisubstituted pyrroles bearing both a trifluoromethyl and alkyl(aryl)thio group at 3- and 4-positions.
α-Effect with Substituted <i>N</i>-Methylbenzohydroxamates and Substituted Phenyldimethylsulfonium Salts: Toward Understanding of an Intrinsic α-Effect
作者:K. R. Fountain、Timothy W. Dunkin、Kamlesh D. Patel
DOI:10.1021/jo9620021
日期:1997.5.1
ium ions decreases the alpha-effect for the methyl transfers toward 1.0 (zero effect). An extrapolation shows the possibility of an inverse effect (<1.0). The reactivity of G-NMBH anions correlates with SET parameters and with the known propensity of phenyldimethylsulfonium ions to accept a single electron into a sigma C-S orbital concomitant with expulsion of a CH(3) group. These correlations indicate
McCurdy, Alison; Jimenez, Leslie; Stauffer, David A., Journal of the American Chemical Society, 1992, vol. 114, # 26, p. 10314 - 10321
作者:McCurdy, Alison、Jimenez, Leslie、Stauffer, David A.、Dougherty, Dennis A.
DOI:——
日期:——
Correlations of p<i>K</i><sub>lg</sub><sup>Me</sup> with Reduction Potentials
作者:K. R. Fountain、Kamlesh D. Patel、Timothy W. Dunkin、Janette A. Powers、Dean A. Van Galen
DOI:10.1021/jo961658r
日期:1997.2.1
The quantitative indices for the ability of leaving groups to depart from C atoms are pK(lg)(Me). In the cases of methyl transfers from arenesulfonates, these parameters have correlated a large number of nucleophilic data. A new scale of these parameters has been defined from methyl transfer data between phenylmethyl thioethers. The pK(lg)(Me) data from both sets of compounds correlated with both experimental E(1/2) values and E(LUMO) values from computational chemistry. These correlations support the SCM model of Shaik et al. which requires the leaving group to display some SET character in an S(N)2 transition state.