82902-62-3Relevant academic research and scientific papers
Suzuki cross-coupling reactions between alkenylboronic acids and aryl bromides catalysed by a tetraphosphane-palladium catalyst
Peyroux, Eugenie,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
, p. 1075 - 1082 (2007/10/03)
A range of alkenylboronic acids undergo Suzuki cross-coupling with aryl bromides in good yields in the presence of [PdCl(C3H 5)]2/cis,cis,cis-1,2,3,4-tetrakis[(diphenylphosphanyl) methyl]cyclopentane as a catalyst. A wide variety of 1-arylprop-1-enes, 2-arylprop-1-enes, 2-arylbut-1-enes and 1,1-diarylethylene or styrene derivatives have been prepared. Moreover, the reaction tolerates several functions, such as acetyl, formyl, nitrile or nitro. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Synthesis of polysubstituted alkenes by Heck vinylation or Suzuki cross-coupling reactions in the presence of a tetraphosphane-palladium catalyst
Berthiol, Florian,Doucet, Henri,Santelli, Maurice
, p. 1091 - 1096 (2007/10/03)
Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3, 4-tetrakis[(diphenylphosphanyl)methyl]cyclopentane as a catalyst, a range of vinyl bromides undergo Suzuki cross-couplings with arylboronic acids in good yields. Furthermore, the catalyst can be used at low loadings, even for reactions of sterically hindered substrates. Mediated by this catalyst, stilbene and 1,1-diphenylethylene undergo Heck reactions with aryl halides to give triarylethylene derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Synthesis and Conversions of Substituted o-[(Trimethylsilyl)methyl]benzyl p-Tolyl Sulfones to o-Quinodimethanes and Products Thereof
Lenihan, Brian D.,Shechter, Harold
, p. 2072 - 2085 (2007/10/03)
Use of o-[(trimethylsilyl)methyl]benzyl p-tolyl sulfone (3) for synthesis and cycloaddition of substituted o-quinodimethanes has been investigated. Sulfone 3 is prepared from 2-methylbenzyl alcohol (4) by reactions with n-BuLi and chlorotrimethylsilane to form o-[(trimethylsilyl)methyl]-benzyl alcohol (7) which phosphorus tribromide converts to o-[(trimethylsilyl)methyl]benzyl bromide (8). Displacement of 8 with sodium p-toluenesulfinate yields 3. Sulfone 3 is alkylated at its α-sulfonyl position upon deprotonation with n-BuLi followed by methyl iodide, ethyl, butyl, allyl, and benzyl bromides, and 5-bromo-1-pentene, respectively. Acylations occur using acid chlorides. Dialkylation occurs upon further reaction with n-BuLi and an alkyl halide. 1,4-Eliminations of α,α-dialkyl sulfones 11 with tetrabutylammonium fluoride (TBAF) give α,α-dialkyl-o-quinodimethanes (29); 3 is therefore a synthon for the o-quinodimethane-α,α-dianion (34). o-Quinodimethanes 29 undergo (1) cycloaddition with acrylonitrile, acrylate esters, and alkyl fumarates to yield 1,1-disubstituted-tetrahydronaphthalenes (30) and (2) 1,5-sigmatropic rear-rangements of hydrogen to give styrenes (32). The stereochemistries of the various cycloadditions reveal significant mechanism information.
Substituted o-benzyl p-Tolyl Sulfones: Practical Reagents for Preparing Cycloadducts of o-Quinodimethanes
Lenihan, Brian D.,Shechter, Harold
, p. 7505 - 7508 (2007/10/02)
Effective methods for synthesis and 1,4-elimination of silyl sulfones to o-quinodimethanes have been developed.
Photochemistry of (o-Methylphenyl)alkenes and the Stereospecific Trapping of the Resulting o-Xylylenes
Hornback, Joseph M.,Barrows, Russel D.
, p. 4285 - 4291 (2007/10/02)
The photochemical behavior of a series of o-methylstyrenes with simple alkyl groups in the α or β positions was investigated in order to determine the synthetic potential of the resulting o-xylylenes.The major photochemical product of all the styrenes employed (1,9,10, and 11) was the corresponding o-xylylene.The o-xylylenes were trapped in acceptable yields by maleic anhydride to give the Diels-Alder adducts.In the case of 9 or 10 and 11 the o-xylylynes were produced stereoselectively and trapped stereospecifically to give 15 or 16 respectively.In the absence ofa dienophile or in the presence of a weak dienophile, such as cyclohexene, a slower isomerization of the o-methylstyrenes to the meta isomers was observed, presumably via a benzvalene intermediate.In addition, the o-xylylene produced from 9 or 10 and 11 underwent geometrical isomerization in the absence of maleic anhydride, resulting in the formation of 10 and 11 upon irradiation of 9 and vice versa.
