Cyclopropylamines from N,N-Dialkylcarboxamides and Grignard Reagents in the Presence of Titanium Tetraisopropoxide or Methyltitanium Triisopropoxide
作者:Armin de Meijere、Vladimir Chaplinski、Harald Winsel、Markus Kordes、Björn Stecker、Vesta Gazizova、Andrei I. Savchenko、Roland Boese、Farina Schill née Brackmann
DOI:10.1002/chem.201001550
日期:2010.12.10
Thirty‐three different N,N‐dialkyl‐ and N‐alkyl‐N‐phosphorylalkyl‐substituted carboxamides 9–17 were treated with unsubstituted as well as with 2‐alkyl‐, 2,2‐dialkyl‐, and 3‐alkenyl‐substituted ethylmagnesium bromides 6 in the presence of stoichiometric amounts of titanium tetraisopropoxide or methyltitanium triisopropoxide to furnish substitutedcyclopropylamines 20–25 in 20–98 % yield, depending
Direct Thionation and Selenation of Amides Using Elemental Sulfur and Selenium and Hydrochlorosilanes in the Presence of Amines
作者:Fumitoshi Shibahara、Rie Sugiura、Toshiaki Murai
DOI:10.1021/ol9010882
日期:2009.7.16
Reactions of amides with elemental sulfur in the presence of hydrochlorosilanes and amines give the corresponding thioamides in good to high yields. The process takes place via reduction of elemental sulfur by the hydrochlorosilane in the presence of a suitable amine. The methodology can be applied to the selenation of amides by using elemental selenium. Thionation and selenation of an acetyl-protected
Reduction of amides to amines via catalytic hydrosilylation by a rhodium complex
作者:Ryoichi Kuwano、Masatoshi Takahashi、Yoshihiko Ito
DOI:10.1016/s0040-4039(97)10804-8
日期:1998.2
Reduction of a wide range of tertiary amides with 2 molar equivalents of diphenylsilane was promoted by 0.1 mol% of RhH(CO)(PPh3)3 at room temperature, affording the corresponding tertiary amines in high yields. The synthetic utility is demonstrated by chemoselective reductions of amides having functional groups such as ester and epoxy groups which are not tolerated by the conventional reductions with
Metal-Free Formal Oxidative C−C Coupling by In Situ Generation of an Enolonium Species
作者:Daniel Kaiser、Aurélien de la Torre、Saad Shaaban、Nuno Maulide
DOI:10.1002/anie.201701538
日期:2017.5.15
contemporary organic synthesis relies on transformations that are driven by the intrinsic, so‐called “natural”, polarity of chemical bonds and reactive centers. The design of unconventionally polarized synthons is a highly desirable strategy, as it generally enables unprecedented retrosynthetic disconnections for the synthesis of complex substances. Whereas the umpolung of carbonyl centers is a well‐known
Copper-catalyzed oxidative desulfurization–oxygenation of thiocarbonyl compounds using molecular oxygen: an efficient method for the preparation of oxygen isotopically labeled carbonyl compounds
A novel copper-catalyzed oxidative desulfurization reaction of thiocarbonyl compounds, using molecular oxygen as an oxidant and leading to formation of carbonyl compounds, has been developed, and the utility of the process is demonstrated by its application to the preparation of a carbonyl-18O labeled sialic acid derivative.