60617-89-2Relevant articles and documents
Reductive activation and hydrofunctionalization of olefins by multiphoton tandem photoredox catalysis
Czyz, Milena L.,Taylor, Mitchell S.,Horngren, Tyra H.,Polyzos, Anastasios
, p. 5472 - 5480 (2021/06/01)
The conversion of olefin feedstocks to architecturally complex alkanes represents an important strategy in the expedient generation of valuable molecules for the chemical and life sciences. Synthetic approaches are reliant on the electrophilic activation of unactivated olefins, necessitating functionalization with nucleophiles. However, the reductive functionalization of unactivated and less activated olefins with electrophiles remains an ongoing challenge in synthetic chemistry. Here, we report the nucleophilic activation of inert styrenes through a photoinduced direct single electron reduction to the corresponding nucleophilic radical anion. Central to this approach is the multiphoton tandem photoredox cycle of the iridium photocatalyst [Ir(ppy)2(dtbbpy)] PF6, which triggers in situ formation of a high-energy photoreductant that selectively reduces styrene olefinic π bonds to radical anions without stoichiometric reductants or dissolving metals. This mild strategy enables the chemoselective reduction and hydrofunctionalization of styrenes to furnish valuable alkane and tertiary alcohol derivatives. Mechanistic studies support the formation of a styrene olefinic radical anion intermediate and a Birch-type reduction involving two sequential single electron transfers. Overall, this complementary mode of olefin activation achieves the hydrofunctionalization of less activated alkenes with electrophiles, adding value to abundant olefins as valuable building blocks in modern synthetic protocols.
Nickel-catalyzed anti-Markovnikov hydroarylation of alkenes
Nguyen, Julia,Chong, Andrea,Lalic, Gojko
, p. 3231 - 3236 (2019/03/21)
We have developed a nickel-catalyzed hydroarylation of alkenes using aryl halides as coupling partners. Excellent anti-Markovnikov selectivity is achieved with aryl-substituted alkenes and enol ethers. We also show that hydroarylation occurs with alkyl substituted alkenes to yield linear products. Preliminary examination of the reaction mechanism suggests irreversible hydrometallation as the selectivity determining step of the hydroarylation.
Ligand-Controlled Nickel-Catalyzed Reductive Relay Cross-Coupling of Alkyl Bromides and Aryl Bromides
Peng, Long,Li, Yuqiang,Li, Yangyang,Wang, Wang,Pang, Hailiang,Yin, Guoyin
, p. 310 - 313 (2018/01/17)
1,1-Diarylalkanes are important structural frameworks which are widespread in biologically active molecules. Herein, we report a reductive relay cross-coupling of alkyl bromides with aryl bromides by nickel catalysis with a simple nitrogen-containing ligand. This method selectively affords 1,1-diarylalkane derivatives with good to excellent yields and regioselectivity.
Zinc chloride enhanced arylations of secondary benzyl trifluoroacetates in the presence of b-hydrogen atoms
Duan, Hui,Meng, Lingkui,Bao, Denghui,Zhang, Heng,Li, Yao,Lei, Aiwen
supporting information; experimental part, p. 6387 - 6390 (2010/11/04)
Zinc or swim: Arylation of benzyl trifluoroacetates with arylzinc reagents in the presence of β- hydrogen atoms were realized under mild conditions. Both electron-rich and electron-deficient arene substrates were successfully arylated. This arylation method could offer a very versatile synthetic route to access a series of diversity-oriented diarylalkane motifs. TFA = trifluoroacetyl. Copyright
Facile and catalytic degradation method of DDT using Pd/C-Et3N system under ambient pressure and temperature
Monguchi, Yasunari,Kume, Akira,Sajiki, Hironao
, p. 8384 - 8392 (2007/10/03)
The catalytic degradation method of p,p′-DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] and its regioisomer o,p′-DDT [1,1,1-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane] using the Pd/C-Et3N system under ambient hydrogen pressure and temperature was established. The presence of Et3N was necessary for the quick and complete breakdown of DDT. The independent degradation study of two intermediates, p,p′-DDD [2,2-bis(p-chlorophenyl)-1,1-dichloroethane] and p,p′-DDE [2,2-bis(p-chlorophenyl)-1,1-dichloroethylene] using GC-MS let us to speculate the degradation pathway of p,p′-DDT. In the initial phase of the reaction, p,p′-DDT degradation splits into two ways: a dehydrochlorination pathway and a hydrodechlorination pathway. In each pathway, reaction starts from an aliphatic moiety and subsequent hydrodechlorination from the benzene moieties takes place in a stepwise manner. The former pathway leads to the formation of 1,1-diphenylethane and the latter leads to the formation of 1,1-dichloro-2,2-diphenylethane. These diphenylethane analogs, which are less toxic compared with p,p′-DDT, are terminal degradation products in our system. The distinctive features of our catalytic degradation method of DDTs are reliability, simplicity, efficiency, and inexpensiveness.
The first complete dechlorination of 1,1,1-trichloro-2,2-bis(4- chlorophenyl) ethane (P,P'-DDT) using metal-promoted alkoxyborohydride in a protic solvent
Tabaei, Seyed-Mohammad H.,Satarinezhad, Elaheh,Seradj, Seyed-Hassan,Ebrahimian, Gholam-Reza
, p. 43 - 51 (2007/10/03)
The reaction in situ of sodium borohydride with 2-methoxyethanol in 2- propanol in the presence of catalytic amount of NiCl2 · 6H2O generates a powerful dechlorinating system which dechlorinates 1,1,1-trichloro-2,2-bis (4-chlorophenyl)-ethane (DDT) to 1,1-diphenylmethoxymethane(80%) and 1-(p- chlorophenyl)-1-phenylethane(10%) in 6 hours at 82-84 °C.
Indium trichloride catalyzed reductive Friedel-Crafts alkylation of aromatics using carbonyl compounds
Miyai, Takashi,Onishi, Yoshiyuki,Baba, Akio
, p. 6291 - 6294 (2007/10/03)
Reductive Friedel-Crafts alkylation of aromatics with aldehydes or ketones using chlorodimethylsilane as a hydride source was effectively promoted by a catalytic amount of indium trichloride, whereas a popular type of Friedel-Crafts catalysts showed less effect.
Electrolytic Dechlorination of DDT In a Bicontinuous Microemulsion
Schweizer, Silvia,Rusling, James F.,Huang, Qingdong
, p. 961 - 970 (2007/10/03)
Electrolytic reduction in a bicontinuous microemulsion of surfactant, oil, and water removed aliphatic and aromatic chlorines from DDT. Microemulsions of didodecyldimethylammonium bromide/dodecane/water used with graphite felt cathodes provided a less expensive, less toxic approach to DDT electrolysis compared to using conventional organic solvents and metal electrodes. Good rates of aliphatic dechlorination were achieved by applying -1 V vs. Ag/AgBr and using the catalyst Co(bpy)32+, but the best yield (34 percent in 3 hr) of the fully dechlorinated hydrocarbon 1,1-diphenylethane was achieved by using -2 V with oxygen in the reaction medium.
PULSE MICROREACTOR PESTICIDES HYDRODECHLORINATION
Weiss, A. H.,LaPierre, R. B.
, p. 111 - 122 (2007/10/02)
Catalytic hydrodechlorination of chlorinated pesticides and other environmentally chlorinated materials into lower chlorine content compounds has been studied in a pulse microreactor .Chlorine can be catalytically removed and replaced by hydrogen to prduce partially chlorinated intermediates as well as completely dechlorinated hydrocarbons.Intermediates are equivalent to some of those obtained by natural degradation.The pulse microreactor is a simple technique to predict both product composition and reaction severity required for laboratory scale preparation of such degradation products.