Selective Dimerisation and Addition of Carboxylic Acids to Terminal Alkynes, Catalysed by Thermolysed Grubbs’ Catalyst: A Novel Synthesis of Enynes and Vinyl Esters
Carboxylic acids react with terminalalkynes in the presence of a catalytic amount of RuClx(p-cymene)(triazol-5-ylidene) to selective generate Z-alk-1-en-1-yl esters. The anti-Markovnikov and trans addition on the terminalalkyne gives access to Z-alkene derivatives of phenylacetylene, t-butylacetylene, 1-octyne, 4-pentynoic acid and 1,7-octadiyne. The dimerization of terminalalkynes catalyzed with the same
Stereochemically pure (E)- and (Z)-alk-1-en-1-yl acetates have been easily prepared by acetoxylation of the (Z)- and (E)-alk-1-en-1-ylboronic acids or their esters, respectively, with (diacetoxyiodo)benzene and sodium iodide, in reasonable yields.
Synthesis of Enol Esters and Dimerization of Terminal Alkynes Catalyzed by Neutral and Cationic Vinylidene Ruthenium Complexes
作者:Francis Verpoort、Tom Opstal
DOI:10.1055/s-2003-37106
日期:——
In the current study Ru(II) vinylidene complexes of the general type: Cl 2 Ru=C=C(H)R}(PR' 3 )L (R = Ph, SiMe 3 , R'=Ph, Cyclohexyl (Cy) and L = phosphine or N-heterocyclic carbene) are synthesized and tested for the addition of carboxylic acids to terminalalkynes. A careful choice of the catalytic system, substrate and carboxylic acid gives access to alk-1-en-2-yl esters, alk-1-en-1-yl esters or
Ru-mediated selective addition reactions of carboxylic acids to internal and terminal alkynes
作者:Solmaz Karabulut、Bengi Özgün Öztürk、Yavuz İmamoğlu
DOI:10.1016/j.jorganchem.2010.05.018
日期:2010.9
towards carboxylic acid addition to the triple bond of terminalalkynes, rather than triple bond addition to the double bond of the enoic acids. To evaluate the results obtained from the carboxylic acid addition reaction of terminalalkynes, the homodimerisation of terminalalkynes (phenylacetylene, 1-octyne, 1-heptyne) was also studied. The homodimerisation of terminalalkynes is found to proceed