Gold-Catalyzed Carbene Transfer to Alkynes: Access to 2,4-Disubstituted Furans
作者:Søren Kramer、Troels Skrydstrup
DOI:10.1002/anie.201200307
日期:2012.5.7
example of a gold‐catalyzed intermolecular addition of carbon ylides to terminal alkynes is reported (see scheme; DCE=dichloroethane, Tf=trifluoromethanesulfonyl). Subsequent intramolecular trapping of the generated gold carbene completes a formal [3+2] cycloaddition, which represents a novel synthesis of 2,4‐disubstituted furans.
ophenone giving α-phenylthio-α-methylthio ketones. The methylthio transfer reaction between the ketone α-positions was reversible and at equilibrium, and the methylthio group was transferred in preference to the phenylthio group. The reaction of tertiary alkyl methylthiomethyl ketones proceeded in high yields; the reaction of diastereomeric 4-(tert-butyl)-2-phenylthiocyclohexanones gave an axial 2-methylthiolated
Elaboration of 1-benzoyltetrahydroisoquinoline derivatives employing a Pictet–Spengler cyclization with α-chloro-α-phenylthioketones. Synthesis of O-methylvelucryptine
作者:Claudio C Silveira、Carmem R Bernardi、Antonio L Braga、Teodoro S Kaufman
DOI:10.1016/s0040-4039(01)01998-0
日期:2001.12
N-tosyl-β-phenethylamines with α-chloro-α-phenylthioketones, leading to 1-benzoyl- and 1-pivaloyl-tetrahydroisoquinolines under modified Pictet–Spengler conditions, is described. The synthesis of O-methylvelucryptine employing this transformation as a key step is reported.
A New Route for Generation of α-λ<sup>3</sup>-Iodanyl Ketones via Ester Exchange of (<i>Z</i>)-(β-Acetoxyvinyl)-λ<sup>3</sup>-iodanes: Their Nucleophilic Substitutions with Halides and Sulfur and Phosphorus Nucleophiles
作者:Masahito Ochiai、Junichi Nishitani、Yoshio Nishi
DOI:10.1021/jo0107711
日期:2002.6.1
An efficient method for generation of alpha-lambda3-iodanyl ketones from (Z)-(2-acetoxyvinyl)(phenyl)-lambda3-iodanes was developed. The method involves ester exchange of (Z)-2-acetoxyvinyl-lambda3-iodanes with methanol in the presence of triethylamine. alpha-lambda3-Iodanyl ketones react with a variety of nucleophiles such as halides, thiols, phosphines, phosphinic acids, and phosphates, under the
Decomposition of diazoketones in organic sulfides and sulfoxides: Cyclopropane formation from diazoketones via sulfonium ylides
作者:J. Quintana、M. Torres、F. Serratosa
DOI:10.1016/0040-4020(73)80146-2
日期:1973.1
and sulfoxonium ylides as the primary reaction products, the final products isolated depending upon the relative nucleophilicity of the sulfides compared to that of the corresponding ylides, and on the stability of the ylides. The mechanism, scope and limitations of a new method of cyclopropane formation from diazoketones are discussed. Some circumstantial evidence supporting a concerted process for Wolff