4586-91-8Relevant academic research and scientific papers
A Relay Strategy Actuates Pre-Existing Trisubstituted Olefins in Monoterpenoids for Cross-Metathesis with Trisubstituted Alkenes
Bahou, Karim A.,Braddock, D. Christopher,Meyer, Adam G.,Savage, G. Paul,Shi, Zhensheng,He, Tianyou
, p. 4906 - 4917 (2020/04/10)
A retrosynthetic disconnection-reconnection analysis of epoxypolyenes - substrates that can undergo cyclization to podocarpane-type tricycles - reveals relay-actuated Δ6,7-functionalized monoterpenoid alcohols for ruthenium benzylidene catalyzed olefin cross-metathesis with homoprenyl benzenes. Successful implementation of this approach provided several epoxypolyenes as expected (E/Z, ca. 2-3:1). The method is further generalized for the cross-metathesis of pre-existing trisubstituted olefins in other relay-actuated Δ6,7-functionalized monoterpenoid alcohols with various other trisubstituted alkenes to form new trisubstituted olefins. Epoxypolyene cyclization of an enantiomerically pure, but geometrically impure, epoxypolyene substrate provides an enantiomerically pure, trans-fused, podocarpane-type tricycle (from the E-geometrical isomer).
Stable Bromiranium Ions with Weakly-Coordinating Counterions as Efficient Electrophilic Brominating Agents
Ascheberg, Christoph,Bock, Jonathan,Bu?, Florenz,Mück-Lichtenfeld, Christian,Daniliuc, Constantin G.,Bergander, Klaus,Dielmann, Fabian,Hennecke, Ulrich
, p. 11578 - 11586 (2017/08/30)
Electrophilic halogenating agents are an important class of reagents in chemical synthesis. Herein, we show that sterically demanding bromiranium ions with weakly coordinating counterions are highly reactive electrophilic brominating agents. Despite their
Alkyldisulfanium salts: Isolable, electrophilic sulfur reagents competent for polyene cyclizations
Schevenels, Florian T.,Shen, Minxing,Snyder, Scott A.
supporting information, p. 2 - 5 (2017/11/27)
Tools that can effect electrophilic sulfur-promoted cation-π cyclizations are generally lacking, especially using alkylsulfide-based reagents. Herein we report that combining three different 1,2-dithioethers with Cl2 and SbCl5 generates isolable alkyldisulfanium salts that can effect such reactions. These new reagents can install -SMe, -SEt, and -SCH2CH2CF3 in modest, moderate, or good yield on diverse frameworks, including polyenes that terminate with electron-deficient groups. We also show that reagents such as dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF) can accomplish similar chemistry.
Enantiospecific bromonium ion generation and intramolecular capture: A model system for asymmetric bromonium ion-induced polyene cyclisations
Braddock, D. Christopher,Marklew, Jared S.,Thomas, Alexander J. F.
supporting information; experimental part, p. 9051 - 9053 (2011/10/05)
Scalemic bromonium ions generated enantiospecifically by the action of catalytic triflic acid on scalemic regioisomeric bromohydrin derivatives are trapped intramolecularly, enantiospecifically and regioselectively to give bicyclic brominated carbocycles in excellent yield and high enantiomeric excess. This enantiospecific pathway is not significantly perturbed by the addition of a trisubstituted alkene.
Generation of magnesium carbenoids from 1-chloroalkyl phenyl sulfoxides with a Grignard reagent and applications to alkylation and olefin synthesis
Satoh, Tsuyoshi,Kondo, Atsushi,Musashi, Jun
, p. 5453 - 5460 (2007/10/03)
Treatment of 1-chloroalkyl phenyl sulfoxides with a Grignard reagent at low temperature gave magnesium carbenoids in quantitative yields. The generated magnesium carbenoids were found to be stable at lower than -60°C for long periods of time and are reactive with Grignard reagents to give alkylated products. The reaction of the generated magnesium carbenoids with various kinds of lithium α-sulfonyl carbanions gave olefins with carbon-carbon bond-formation in good to high yields. This method offers a good way for the preparation of olefins. The scope and limitations of the above-mentioned reactions are described.
A facile synthesis of 1,5-dienes by a regioselective allylation of the allylic arbanions generated from allyl phenyl selenides
Nishitani,Mimaki,Sato,Yamakawa
, p. 288 - 290 (2007/10/02)
Allyl-allyl or benzyl coupling reactions were effected by allyl carbanions, generated from allyl phenyl selenides and n-butyllithium, and allylic or benzylic halides. The ambident selectivities of the allyl carbanions are depending on the solvent system.
NOVAL SYNTHESIS OF 1,3,5-TRISELENANES FROM ALDEHYDES, AND NOVEL GENERATION OF SELENOALDEHYDES BY FRAGMENTATION OF 1,3,5-TRISELENANES
Takikawa, Yuji,Uwano, Akira,Watanabe, Hiroyuki,Asanuma, Masaki,Shimada, Kazuaki
, p. 6047 - 6050 (2007/10/02)
Reaction of aldehydes with (Me3Si)2Se in the presence of Lewis acid afforded 1,3,5-triselenanes via selenoaldehydes.Novel and convenient generation of selenoaldehydes was also achived by thermally- or Lewia acid-induced fragmentation of 1,3,5-triselenanes.
