be very effective for the formation of monocyclic titanacyclopentenes in excellent yields. On the other hand, a combination of Cp2TiCl2–2n-BuLi was used for intermolecular coupling of two alkynes to form titanacyclopentadienes in good to excellent yields. A reaction temperature range from −10 to −30 °C was critical for the success of the combinations. Reactions of these in situ-prepared titanacycles
Catalytic Carbometalation/Cross-Coupling Sequence across Alkynyl(2-pyridyl)silanes Leading to a Diversity-Oriented Synthesis of Tamoxifen-Type Tetrasubstituted Olefins
作者:Toshiyuki Kamei、Kenichiro Itami、Jun-ichi Yoshida
DOI:10.1002/adsc.200404220
日期:2004.12
A general synthetic scheme for tamoxifen-typetetrasubstitutedolefins based on the novel Cu-catalyzed carbomagnesation acrossalkynyl(2-pyridyl)silane has been developed. A wide array of electronically and structurally diverse tetrasubstitutedolefins can be prepared in a regiocontrolled, stereocontrolled, and diversity-oriented manner. Noteworthy features are that (i) the three aryl groups, which
A general and stereoselective method for synthesis of tri- and tetrasubstituted alkenes
作者:I Maciągiewicz、P Dybowski、A Skowrońska
DOI:10.1016/s0040-4020(03)00977-3
日期:2003.8
A convenient, general and stereoselectivesynthesis of trisubstituted alkenes and tetrasubstituted alkenes containing a cyanide function as well as trisubstituted episulphides have been elaborated. Methodology described for the preparation of these compounds is based on the corresponding readily available selenophosphates 1 and thiophosphates 2.
Yttrium-Mediated Conversion of Vinyl Grignard Reagent to a 1,2-Dimetalated Ethane and Its Synthetic Application
作者:Ryoichi Tanaka、Hiroaki Sanjiki、Hirokazu Urabe
DOI:10.1021/ja077992u
日期:2008.3.1
ethane was generated from a vinyl Grignard reagent in the presence of yttrium(III) chloride, sodium cyclopentadienide, and diisobutylaluminum hydride (Dibal). This reagent enables the regio- and stereoselective (metaloethyl)metalation of acetylenes to produce ethylated alkenes after hydrolysis. In addition to simple hydrolysis, further carbon−carbon bond formation or functionalization at the metaloethyl
Regioselective Synthesis of α-Functional Stilbenes via Precise Control of Rapid <i>cis</i>–<i>trans</i> Isomerization in Flow
作者:Hyune-Jea Lee、Yuya Yonekura、Nayoung Kim、Jun-ichi Yoshida、Heejin Kim
DOI:10.1021/acs.orglett.1c00538
日期:2021.4.16
The rapid cis–trans isomerization of α-anionic stilbene was regioselectively controlled by using flow microreactors, and its reaction with various electrophiles was conducted. The reaction time was precisely controlled within milliseconds to seconds at −50 °C to selectively give the cis- or trans-isomer in high yields. This synthetic method in flow was well-applied to synthesize precursors of commercial