286376-23-6Relevant articles and documents
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.
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.
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
