Fluorinated biphenyls from aromatic arylations with pentafluorobenzenediazonium and related cations. Competition between arylation and azo coupling
作者:Dmitry Kosynkin、T. Michael Bockman、Jay K. Kochi
DOI:10.1039/a701745f
日期:——
High yields of the mixed perfluorinated biaryls (C6F5–Ar) are obtained by the catalytic dediazoniation of the pentafluorobenzenediazonium salt (C6F5N2+BF4–) in acetonitrile solutions containing various aromatic substrates (ArH) together with small amounts of iodide salts. Activated (electron-rich) as well as deactivated (electron-poor) arenes are successfully pentafluorophenylated by this method. The arylation is distinct from the azo coupling of the same substrates, which takes place in the absence of the iodide catalyst and yields the corresponding diazene (C6F5NN–Ar) as product. The catalytic role of iodide, and the isomeric product distributions obtained with this procedure indicate that the arylation proceeds via the pentafluorophenyl radical in a efficient homolytic chain process. Since azo coupling involves electrophilic aromatic substitution of electron-rich ArH by C6F5N2+, the two competing pathways are distinct and do not have reactive intermediates in common.
Thermal (Iodide) and Photoinduced Electron-Transfer Catalysis in Biaryl Synthesis <i>via</i> Aromatic Arylations with Diazonium Salts
作者:D. Kosynkin、T. M. Bockman、J. K. Kochi
DOI:10.1021/ja970599b
日期:1997.5.1
oxidant. The complex kinetics of such an electron-transfer chain or ETC process (Scheme 1) is quantitatively verified by computer simulation of the Ar‘H-dependent (a) competition between arylation vs iodination and (b) catalytic efficiency of iodide, using the GEAR algorithms. ETC catalysis also pertains to the alternative photochemical procedure for arylation (in the absence of iodide), in which the deliberate
The present invention provides a process for preparing quinolonecarboxylic acid derivatives having the formula (I):
1
wherein R
1
is H, halogen, or amino; R
2
is halogen; R
3
is H, halogen, C
1-4
alkoxyl, or CN; R
4
is selected from the group consisting of C
3-6
cycloalkyl, C
1-4
alkyl, C
1-4
alkoxyC
1-4
alkyl, and C
1-4
alkylaminoC
1-4
alkyl. The invention also provides new acetophenones having the formula (II) that are intermediates for preparing the compound of the formula (I).
The present invention provides a process for preparing quinolonecarboxylic acid derivatives having the formula (I):
wherein R1 is H, halogen, or amino; R2 is halogen; R3 is H, halogen, C1-4 alkoxyl, or CN; R4 is selected from the group consisting of C3-6cycloalkyl, C1-4alkyl, C1-4alkoxyC1-4alkyl, and C1-4alkylaminoC1-4alkyl. The invention also provides new acetophenones having the formula (II) that are intermediates for preparing the compound of the formula (I).
A NEW PROCESS FOR PREPARING A QUINOLONE-CARBOXYLIC ACID
申请人:Lynchem Co., Ltd.
公开号:EP1319656A1
公开(公告)日:2003-06-18
The present invention provides a process for preparing quinolinecarboxylic acid derivatives having the formula (I):
wherein R1 is H, halogen, or amino; R2 is halogen; R3 is H, halogen, C1-4 alkoxyl, or CN; R4 is selected from the group consisting of C3-6cycloalkyl, C1-4alkyl, C1-4 alkoxyC1-4alkyl, and C1-4alkylaminoC1-4alkyl. The invention also provides new acetophenones having the formula (II) that are intermediates for preparing the compound of the formula (I).