286376-23-6Relevant academic research and scientific papers
Alkynyl triazenes enable divergent syntheses of 2-pyrones
Tan, Jin-Fay,Bormann, Carl Thomas,Severin, Kay,Cramer, Nicolai
, p. 9140 - 9145 (2021/07/12)
The 2-pyrone motif occurs frequently in bioactive natural products and is appreciated as synthetic intermediates. However, only few methods allow for diversifying functional group modifications on this relevant heterocycle. The distinct properties of 1-alkynyl triazenes promote a smooth addition of propiolic acids across the triple bond. Addition of catalytic amounts of silver salt induces cyclization to 2-pyrones. Depending on the reaction temperature, either 6-triazenyl or 5-triazenyl 2-pyrones are selectively formed. The triazenyl unit is subsequently replaced by a variety of valuable groups in a one-pot process yielding for instance 2-fluoro pyrones. The substitution occurs with an intriguing 1,5-carbonyl transposition. Moreover, the triazenyl group serves as traceless activating group for subsequent Diels-Alder cycloadditions and as a constituting unit for rare fused aminopyrazole pyrone heterocycles.
Rhodium-Catalyzed [2+2+2] Cycloaddition Reactions of Linear Allene–Ene–Ynes to afford Fused Tricyclic Scaffolds: Insights into the Mechanism
Cassú, Daniel,Parella, Teodor,Solà, Miquel,Pla-Quintana, Anna,Roglans, Anna
supporting information, p. 14889 - 14899 (2017/10/27)
Allene-(E)-ene-yne N-tosyl-tethered substrates 3 a–3 h were efficiently prepared and their rhodium-catalyzed [2+2+2] cycloaddition reactions were evaluated. The cycloadditions are chemoselective as only the proximal double bond of the allene reacted to af
Ligand-Controlled Cobalt-Catalyzed Transfer Hydrogenation of Alkynes: Stereodivergent Synthesis of Z- and E-Alkenes
Fu, Shaomin,Chen, Nan-Yu,Liu, Xufang,Shao, Zhihui,Luo, Shu-Ping,Liu, Qiang
supporting information, p. 8588 - 8594 (2016/07/27)
Herein, we report a novel cobalt-catalyzed stereodivergent transfer hydrogenation of alkynes to Z- and E-alkenes. Effective selectivity control is achieved based on a rational catalyst design. Moreover, this mild system allows for the transfer hydrogenation of alkynes bearing a wide range of functional groups in good yields using catalyst loadings as low as 0.2 mol %. The general applicability of this procedure is highlighted by the synthesis of more than 50 alkenes with good chemo- and stereoselectivity. A preliminary mechanistic study revealed that E-alkene product was generated via sequential alkyne hydrogenation to give Z-alkene intermediate, followed by a Z to E alkene isomerization process.
Chiral pyrrolidines and piperidines from enantioselective rhodium-catalyzed cascade arylative cyclization
Serpier, Fabien,Flamme, Benjamin,Brayer, Jean-Louis,Folléas, Beno?t,Darses, Sylvain
supporting information, p. 1720 - 1723 (2015/04/14)
A new rhodium-catalyzed asymmetric arylative cyclization of nitrogen-tethered alkyne-enoate with arylboronic acids is described. In this process two new carbon-carbon bonds and one stereocenter are formed, providing access to pyrrolidines and piperidines
Secondary phosphine oxide-gold(I) complexes and their first application in catalysis
Schroeder, Felix,Tugny, Coralie,Salanouve, Elise,Clavier, Herve,Giordano, Laurent,Moraleda, Delphine,Gimbert, Yves,Mouries-Mansuy, Virginie,Goddard, Jean-Philippe,Fensterbank, Louis
supporting information, p. 4051 - 4056 (2014/10/15)
A series of new secondary phosphine oxide (SPO)-gold(I) complexes have been synthesized and characterized by X-ray crystallography. Complexes exhibited dimeric structures interconnected by O-H···Cl hydrogen bonds. Their first use in homogeneous catalysis
Enantioselective IrI-catalyzed carbocyclization of 1,6-enynes by the chiral counterion strategy
Barbazanges, Marion,Auge, Mylene,Moussa, Jamal,Amouri, Hani,Aubert, Corinne,Desmarets, Christophe,Fensterbank, Louis,Gandon, Vincent,Malacria, Max,Ollivier, Cyril
, p. 13789 - 13794 (2012/01/06)
Enantioenriched bicyclo[4.1.0]hept-2-enes were synthesized by Ir I-catalyzed carbocyclization of 1,6-enynes. No chiral ligands were used, CO and PPh3 were the only ligands bound to iridium. Instead, the stereochemical information was
(Pentamethylcyclopentadienyl)iridium dichloride dimer {[IrCp*Cl 2]2}: A novel efficient catalyst for the cycloisomerizations of homopropargylic diols and N-tethered enynes
Benedetti, Erica,Simonneau, Antoine,Hours, Alexandra,Amouri, Hani,Penoni, Andrea,Palmisano, Giovanni,Malacria, Max,Goddard, Jean-Philippe,Fensterbank, Louis
supporting information; experimental part, p. 1908 - 1912 (2011/10/05)
(Pentamethylcyclopentadienyl)iridium dichloride dimer {[IrCp*Cl 2]2}-catalyzed hydroalkoxylation of bis-homopropargylic alcohols provides an efficient access to dioxabicyclo[2.2.1]ketals. The cycloisomerizations proceed under mild conditions, with low catalytic loadings and short reaction times. This new protocol involving an Ir(III) catalyst also promoted the cycloisomerization of nitrogen-tethered 1,6-enynes to give azabicyclo[4.1.0]heptenes, enhancing the synthetic potential of our method. Copyright
Rhodium-catalysed alkoxycarbonylative cyclisation reactions of 1,6-enynes
Ziyanak, Firat,Kus, Melih,Artok, Levent
supporting information; experimental part, p. 897 - 902 (2011/06/22)
The rhodium-catalysed carbonylation of 1,6-enynes possessing an electron-deficient alkenyl moiety in an alcohol reagent in the presence of a rhodium complex proceeded stereo- and chemoselectively to afford exocyclic α,β-enoates.
Rhodium-catalyzed synthesis of γ-butyrolactams and pyrrolidines via cycloisomerization of N-tethered 1,6-enynes
Wang, Jianping,Xie, Xiaomin,Ma, Fangfang,Peng, Zhiyong,Zhang, Lei,Zhang, Zhaoguo
experimental part, p. 4212 - 4217 (2010/07/05)
A rhodium-catalyzed cycloisomerization reaction of N-tethered 1,6-enynes with an intramolecular halogen shift has been developed, providing a useful process for the synthesis of stereo defined γ-butyrolactam and pyrrolidine derivatives in good to excellent yields. Effects of both electronic feature and steric structure of the substrates on the outcome of the reaction were investigated.
Stereocontrolled preparation of bicyclic alkaloid analogues: an approach towards the kinabalurine skeleton
Kavanagh, Yvonne,O'Brien, Matthew,Evans, Paul
experimental part, p. 8259 - 8268 (2009/12/24)
An approach towards the construction of bicyclic analogues of monoterpene alkaloids belonging to the kinabalurine, incarvilline and skytanthine families of natural products is reported. These syntheses rely on a stereoselective intramolecular Pauson-Khand
