68578-76-7Relevant academic research and scientific papers
Catalytic photocarboxylation of 1,1-diphenylethylene with N,N,N′,N′-tetramethylbenzidine and carbon dioxide
Ito, Yoshikatsu
, p. 3108 - 3114 (2007/10/03)
Photocarboxylation of 1,1-diphenylethylene with N,N,N′,N′-tetramethylbenzidine (TMB) in MeCN under bubbling of CO2 proceeded with high catalytic efficiency, giving 3,3-diphenylacrylic acid (DPA) and 3-hydroxy-3,3-diphenylpropionic acid (20). The turnover number (TON=(DPA+20)/TMB) reached 17. Similarly, 1-phenyl-1-cyclohexene yielded cis-2-acetamido-2-phenylcyclohexanecarboxylic acid with TON 5.9. As compared with related N,N-dimethylaniline derivatives, TMB is more resistant to photodecomposition, has the much larger absorbance in the S0→S1 transition, and has the lower quenching efficiency by CO2. Probably these factors are partly responsible for the high TON observed for TMB.
Photoinduced, ionic Meerwein arylation of olefins
Mella,Coppo,Guizzardi,Fagnoni,Freccero,Albini
, p. 6344 - 6352 (2007/10/03)
Irradiation of 4-chloroaniline or of its N,N-dimethyl derivative in polar solvents generates the corresponding triplet phenyl cations. These are trapped by alkenes yielding arylated products in medium to good yields. B3LYP calculations show that the triplet cation slides with negligible activation energy to a bonded adduct with ethylene, whereas it forms only a marginally stabilized CT complex with water (chosen as a representative σ nucleophile). The structure of the final products depends on the preferred path from the adduct cation with the alkene. In the case of aryl olefins, this deprotonates to stilbene derivatives, while, from 2,3-dimethyl-2-butene and allytrimethylsilane, allylanilines are obtained by elimination of an electrofugal group in γ. In the case of mono- and disubstituted alkenes the cation adds chloride rather than eliminating and β-chloroalkylanilines are obtained. The regio- and sterochemistry of the addition across the alkene are best understood with a phenonium ion structure for the adduct. The nucleophile entering in fi can be varied under conditions in which the adduct cation is trapped more efficiently than the starting phenyl cation. Thus, β-methoxyalkylanilines are formed when the irradiation is carried out in methanol. β-Iodoalkylanilines are obtained in acetonitrile containing iodide and unsubstituted alkylanilines in the presence of sodium borohydride. A case of intramolecular nucleophilic trapping is found with 4-pentenoic acid. The reaction is a wide-scope ionic analogue of the radicalic Meerwin arylation of olefins.
Smooth synthesis of aryl- and alkylanilines by photoheterolysis of haloanilines in the presence of aromatics and alkenes
Fagnoni, Maurizio,Mella, Mariella,Albini, Angelo
, p. 1299 - 1301 (2008/02/09)
Irradiation of 4-chloro-N,N-dimethylaniline in acetonitrile in the presence of benzene and of various alkenes leads to heterolytic dehalogenation and trapping of the cation. 4-(Dimethylamino)biphenyl is formed in the first case, while with alkenes β-chloroalkylanilines, stilbenes, or allylanilines are obtained depending on the alkene structure. 4-Fluoroaniline is similarly dehalogenated.
