10508-57-3Relevant academic research and scientific papers
Synthesis of substituted 2-amino-1,3-thiazine-6-thiones
Glotova,Komarova,Nakhmanovich,Lopyrev
, p. 1917 - 1918 (2000)
The reaction of thiourea with 1-acyl-2-bromoacetylenes in AcOH in the presence of BF3 · Et2O affords 2-amino-4-phenyl(2-thienyl)-1,3-thiazine-6-thiones in high yields.
Selectivity for Alkynyl or Allenyl Imidamides and Imidates in Copper-Catalyzed Reactions of Terminal 1,3-Diynes and Azides
Ghorai, Sourav,Lee, Daesung
supporting information, p. 697 - 701 (2021/02/01)
Copper-catalyzed reactions of terminal 1,3-diynes with electron-deficient azides to generate either 3-alkynyl or 2,3-dienyl imidamides and imidates are described. The selectivity depends on the diyne substituents and the nucleophile that reacts with the ketenimide intermediate generated from the corresponding triazole precursor. Reactions of 1,3-diynes containing a propargylic acetate afford [3]cumulenyl imidamides, while reactions using methanol as the trapping agent selectively generate 2,3-dienyl imidates. Five-membered heterocycles were obtained from 1,3-diynes containing a homopropargylic hydroxyl or amine substituent.
Benzannulation of triynes to generate functionalized arenes by spontaneous incorporation of nucleophiles
Karmakar, Rajdip,Yun, Sang Young,Chen, Jiajia,Xia, Yuanzhi,Lee, Daesung
supporting information, p. 6582 - 6586 (2015/06/02)
The thermal reaction of ester-tethered 1,3,8-triynes provides novel benzannulation products with concomitant incorporation of a nucleophile. Evidence suggests that this reaction proceeds via an allene-enyne intermediate generated by an Alder-ene reaction in the first step. Depending on the substituent of the alkyne moiety on the allene-enyne intermediate, the subsequent transformation can take one of two different paths, each leading to discrete aromatization products. The benzannulation of a silane-substituted 1,3,8-triynes provides arene products with a nucleophile incorporated onto the newly formed benzene core, whereas an aryl substituent leads to nucleophile trapping at the benzylic carbon atom connected to the aryl substituent. The formation of these two different products results from the involvement of two regioisomeric allene-enyne intermediates.
Synthesis of cyclopentenimines from N-allyl ynamides via a tandem aza-Claisen rearrangement-carbocyclization sequence
Wang, Xiao-Na,Winston-Mcpherson, Gabrielle N.,Walton, Mary C.,Zhang, Yu,Hsung, Richard P.,Dekorver, Kyle A.
, p. 6233 - 6244 (2013/07/26)
We describe here details of our investigations into Pd-catalyzed and thermal aza-Claisen-carbocyclizations of N-allyl ynamides to prepare a variety of α,β-unsaturated cyclopentenimines. The nature of the ynamide electron-withdrawing group and β-substituent plays critical roles in the success of this tandem cascade. With N-sulfonyl ynamides, the use of palladium catalysis is required, as facile 1,3-sulfonyl shifts dominate under thermal conditions. However, since no analogous 1,3-phosphoryl shift is operational, N-phosphoryl ynamides could be used to prepare similar cyclopentenimines under thermal conditions through zwitter ionic intermediates that undergo N-promoted H-shifts. Alternatively, by employing ynamides bearing tethered carbon nucleophiles, the zwitter ionic intermediates could be intercepted, giving rise rapidly to more complex fused bi- and tricyclic scaffolds.
Synthesis of simple diynals, diynones, their hydrazones, and diazo compounds: Precursors to a family of dialkynyl carbenes (R1-C-C- C-C-C-R2)
Bowling, Nathan P.,Burrmann, Nicola J.,Halter, Robert J.,Hodges, Jonathan A.,McMahon, Robert J.
supporting information; experimental part, p. 6382 - 6390 (2010/12/19)
A variety of substituted pentadiynols, -diynals, and -diynones have been prepared en route to precursors to dialkynyl carbenes (R1-C-C-C- C-C-R2). In light of the marginal stability associated with these simple systems, several strategies were required to assemble the carbon backbones. The requisite five-carbon skeletons were prepared using 4 + 1, 3 + 2, 2 + 2 + 1, and 2 + 1 + 1 + 1 coupling methodologies. The Dess-Martin periodinane serves as an excellent method for the oxidation of pentadiynols to diynals and diynones, although many of the oxidized products are sufficiently reactive that they were not isolated; rather, they were generated in situ and intercepted with nucleophiles such as tosylhydrazide or trisylhydrazide. The hydrazone derivatives are generally reliable precursors to diazo compounds and carbenes, although cyclization of the hydrazone to afford a pyrazole can be a complicating factor in certain instances.
Synthesis of isocoumarins and α-pyrones via palladium-catalyzed annulation of internal alkynes
Larock, Richard C.,Doty, Mark J.,Han, Xiaojun
, p. 8770 - 8779 (2007/10/03)
A number of 3,4-disubstituted isocoumarins and polysubstituted α- pyrones have been prepared in good yields by treating halogen- or triflate- containing aromatic and α,β-unsaturated esters, respectively, with internal alkynes in the presence of a palladiu
VALENT ISOMERIZATION OF CARBONYL-CONTAINING NORBORNADIENES
Chenoivanov, V. A.,Dubonosov, A. D.,Bren', V. A.,Minkin, V. I.,Galichev, S. V.,Suslov, A. N.
, p. 1313 - 1316 (2007/10/02)
Norbornadiene derivatives containing aldehydic and ketonic groupings at one of the double bonds were synthesized.On irradiation by filtered light from a mercury lamp in the region of the maximum of the long wave absorption band, the compounds obtained iso
