61658-88-6Relevant articles and documents
Coupling of Reformatsky Reagents with Aryl Chlorides Enabled by Ylide-Functionalized Phosphine Ligands
Hu, Zhiyong,Wei, Xiao-Jing,Handelmann, Jens,Seitz, Ann-Katrin,Rodstein, Ilja,Gessner, Viktoria H.,Goo?en, Lukas J.
supporting information, p. 6778 - 6783 (2021/02/01)
The coupling of aryl chlorides with Reformatsky reagents is a desirable strategy for the construction of α-aryl esters but has so far been substantially limited in the substrate scope due to many challenges posed by various possible side reactions. This limitation has now been overcome by the tailoring of ylide-functionalized phosphines to fit the requirements of Negishi couplings. Record-setting activities were achieved in palladium-catalyzed arylations of organozinc reagents with aryl electrophiles using a cyclohexyl-YPhos ligand bearing an ortho-tolyl-substituent in the backbone. This highly electron-rich, bulky ligand enables the use of aryl chlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively over triflate electrophiles, which permits consecutive coupling strategies.
Benzo polyaza and phosphole oxygen ligand and complex containing same, preparation method and application
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Paragraph 0152; 0153; 0154; 0155; 0156, (2019/01/16)
The invention discloses a benzo polyaza and phosphole oxygen ligand and a complex containing same, a preparation method and application. The invention provides a benzo polyaza and phosphole oxygen ligand as shown in formula I and a complex containing same. A complex of the benzo polyaza and phosphole oxygen ligand and a transition metal halide enables direct coupling of carbon-carbon bonds betweenbig steric hindrance alkyl and aryl; the reaction conditions are gentle; the catalyzing efficiency is high; the coupling reaction process of the carbon-carbon bonds between big steric hindrance alkyland aryl can be extremely simplified; the practicability is high; the reaction cost can be obviously decreased, and the reaction period is reduced; the complex is free from other side products without being required in the catalyzing process. The formula refers to the description.
Aromatic chlorination of ω-phenylalkylamines and ω- phenylalkylamides in carbon tetrachloride and α,α,α- trifluorotoluene
O'Connell, Jenny L.,Simpson, Jamie S.,Dumanski, Paul G.,Simpson, Gregory W.,Easton, Christopher J.
, p. 2716 - 2723 (2008/02/08)
The aromatic halogenation of simple alkylbenzenes with chlorine proceeds smoothly in acetic acid but is much less efficient in less polar solvents. By contrast chlorination of ω-phenylalkylamines, such as 3-phenylpropylamine, occurs readily in either acetic acid, carbon tetrachloride or α,α,α-trifluorotoluene, and in the latter solvents gives high proportions of ortho-chlorinated products. These effects are attributable to the involvement of N-chloroamines as reaction intermediates, with intramolecular delivery of the chlorine electrophile. ω-Phenylalkylamides, such as 3-phenylpropionamide, also easily undergo aromatic chlorination in carbon tetrachloride and α,α,α-trifluorotoluene. These reactions generally show a first-order dependence on the substrate concentration, but not on the amount of chlorine. With carbon tetrachloride, very similar reaction rates are observed with chlorine concentrations ranging from 0.1-1.5 M. In α,α,α-trifluorotoluene, the rates reach a plateau at a chlorine concentration of approximately 0.2 M. These features indicate that the reactions proceed via the formation of intermediates which evidence suggests may be the corresponding O-chloroimidates. Irrespective of the mechanistic details, the reactions are remarkably rapid, being faster than analogous reactions in acetic acid and three to four orders of magnitude more rapid than reactions of simple alkylbenzenes in carbon tetrachloride. Therefore, chlorination of the amines and amides may be accomplished without the need for highly polar solvents, added catalysts or large excesses of chlorine, which are often employed for electrophilic aromatic substitutions. Although the use of carbon tetrachloride is becoming increasingly impractical due to environmental concerns, the trifluorotoluene is a suitable alternative. The Royal Society of Chemistry 2006.
