74104-11-3Relevant academic research and scientific papers
Oxidative addition of N-halosuccinimides to palladium(0): The discovery of neutral palladium(II) imidate complexes, which enhance Stille coupling of allylic and benzylic halides
Crawforth, Catherine M.,Burling, Suzanne,Fairlamb, Ian J. S.,Kapdi, Anant R.,Taylor, Richard J. K.,Whitwood, Adrian C.
, p. 9736 - 9751 (2007/10/03)
The Stille coupling of organostannanes and organohalides, mediated by air and moisture stable palladium(II) phosphine complexes containing succinimide or phthalimide (imidate) ligands, has been investigated. An efficient synthetic route to several palladium(II) complexes containing succinimide and phthalimide ligands, has been developed. cis-Bromobis(triphenylphosphine)(N-succinimide) palladium(II) [(Ph3P)2Pd(N-Succ)Br] is shown to mediate the Stille coupling of allylic and benzylic halides with alkenyl, aryl and allyl stannanes. In competition experiments between 4-nitrobromobenzene and benzyl bromide with a cis-stannylvinyl ester, (Ph3P)2Pd(N-Succ)Br preferentially cross-couples benzyl bromide, whereas with other commonly employed precatalysts 4-nitrobromobenzene undergoes preferential cross-coupling. Furthermore, preferential reaction of deactivated benzyl bromides over activated benzyl bromides is observed for the first time. The type of halide and presence of a succinimide ligand are essential for effective Stille coupling. The type of phosphine ligand is also shown to alter the catalytic activity of palladium(II) succinimide complexes.
Dichloromethane as an unusual methylene equivalent. A new entry of highly nucleophilic and selective titanium-methylene complexes for ester methylenation
Yan, Tu-Hsin,Chien, Ching-Ting,Tsai, Chia-Chung,Lin, Kuo-Wei,Wu, Yen-Hsien
, p. 4965 - 4967 (2007/10/03)
(Chemical Equation Presented) The successful application of CH 2Cl2-Mg-TiCl4-system mediated methylenation of various esters such as tert-butyl ester and 2,5-cyclohexadiene-1-carboxylate highlights the extraordinary reactivity, selectivity, and the nonbasic nature of this new methylene-carbenoid, which serves as a practical reagent applicable to large-scale synthesis.
Efficient and selective Stille cross-coupling of benzylic and allylic bromides using bromobis(triphenylphosphine)(N-succinimide)palladium(II)
Crawforth, Catherine M.,Fairlamb, Ian J. S.,Taylor, Richard J. K.
, p. 461 - 465 (2007/10/03)
Allylic and benzylic bromides are cross-coupled with organostannanes efficiently using the precatalyst [Pd(NCOC2H4CO)(PPh 3)2Br] 1. Significantly, these reactions do not require the use of hexamethylphosphoramide (HMPA) as the solvent, or additional ligands, such as trifurylphosphine or triphenylarsine. Selectivity for benzyl bromide over bromobenzene is observed for precatalyst 1, against the precatalysts, bromobis(triphenylphosphine)(benzyl)palladium(II) and bis(triphenylphosphine) palladium(II) bromide.
2-Ethoxy-2-propenyl Diethyl Phosphate. An Efficient Halo Acetone Equivalent for the Pd-Catalyzed Cross-coupling with Tin Enolates
Kosugi, Masanori,Ohashi, Kenji,Akuzawa, Kazuko,Kawazoe, Takashi,Sano, Hiroshi,Migita, Toshihoko
, p. 1237 - 1238 (2007/10/02)
In the presence of Pd(0) complexes, 2-ethoxy-2-propenyl diethyl phosphate was found to react with organotins to give the corresponding coupling products, showing to be a more efficient halo acetone equivalent compared with the corresponding acetate or carbonate.Reaction with tin enolates gave the 1,4-diketone in moderate to good yields.
Carbonyl Methylenation Using a Titanium- Aluminum (Tebbe) Complex
Pine, Stanley H.,Pettit, Robert J.,Geib, Gregory D.,Cruz, Susana G.,Gallego, Claudio H.,et al.
, p. 1212 - 1216 (2007/10/02)
The titanium-aluminum (Tebbe) complex is shown to be an effective methylenating agent for a variety of carbonyl groups.The reaction is unique in that the carbonyl groups of carboxylic acid derivatives are readily methylenated.Thus vinyl enol ethers are prepared from esters and enamines are formed from amides.The complex provides a method for methylenating hindered or base sensitive ketones that is advantageous to the Wittig reagent.Selective methylenation of dicarbonyl compounds is also accomplished.
