859829-95-1Relevant articles and documents
Synthesis of isocoumarins: Rhenium complex-catalyzed cyclization of 2-ethynylbenzoic acids
Umeda, Rui,Yoshikawa, Shunya,Yamashita, Kouji,Nishiyama, Yutaka
, p. 2172 - 2179 (2015/12/12)
When 2-ethynylbenzoic acids were treated with a catalytic amount of a rhenium complex, such as ReCl(CO)5, 6-endo cyclization of 2-ethynylbenzoic acids proceeded with a high selectivity to give the corresponding isocoumarins in moderate to good yields.
On homogeneous gold/palladium catalytic systems
Hashmi, A. Stephen K.,Lothschuetz, Christian,Doepp, Rene,Ackermann, Martin,De Buck Becker, Janosc,Rudolph, Matthias,Scholz, Christian,Rominger, Frank
supporting information; experimental part, p. 133 - 147 (2012/04/10)
Two substrates containing an aryl iodide and an allenoate ester were prepared and the goldinduced cycloisomerisation to vinylgold(I) species and their proto-deauration as well as the intramolecular palladium-catalysed cross-coupling reactions were investigated. Switching to catalytic amounts of gold and palladium and stoichiometric amounts of silver did indeed furnish the product of a cycloisomerisation/ intramolecular cross-coupling. Control experiments revealed that silver cannot substitute for gold or palladium in these reactions, but a different palladium catalyst in a different oxidation state also afforded the cycloisomerisation/intramolecular crosscoupling products in only slightly reduced yields. By ICP analysis the palladium was shown to contain gold only at the sub-ppm level. This shows how carefully results obtained with such systems have to be interpreted. Then a series of allylic and benzylic o-alkynylbenzoates were investigated in gold-and palladium-catalysed reactions. For esters of benzyl alcohol and cinnamyl alcohol no palladium co-catalyst was needed for the conversion. All reagents were thoroughly checked for palladium traces by ICP analysis in order to thoroughly exclude a gold/palladium cocatalysis. Optimisation of the gold complex, counter ion and solvent showed that gold(I) isonitrile precatalysts and silver triflate as activator in dioxane are suitable to convert a number of substrates with aryl, alkyl and even cyclopropyl substituents. Crossover experiments proved an intermolecular allyl transfer.
Transmission of Polar Effects. Part 21. Alkaline Hydrolysis of the 2'- and 4'-substituted 2-Methoxycarbonyldiphenylacetylenes and (Z)-2'- and -4'- Substituted 2-Methoxycarbonylstilbenes and the Ionisation and Esterification, with Diazodiphenylmethane of t
Bowden, Keith,Ghadir, Khalaf D. F.
, p. 1333 - 1338 (2007/10/02)
The rate coefficients for the alkaline hydrolysis of a series of 2'- and 4'-substituted 2-methoxycarbonyldiphenylacetylenes and (Z)-2-methoxycarbonylstilbenes have been determined in 70percent (v/v) dimethyl sulphoxide-water at both 30.0 and 50.0 deg C an
