844-40-6Relevant articles and documents
One-Pot and Reducible-Functional-Group-Tolerant Synthesis of α-Aryl- and α-Heteroaryl-α-Trifluoromethyl Alcohols via Tandem Trifluoroacetylation and MPV Type Reduction
Funabiki, Kazumasa,Hayakawa, Ayaka,Kani, Ryunosuke,Inuzuka, Toshiyasu,Kubota, Yashuhiro
, p. 5978 - 5984 (2019/08/30)
We have developed a new one-pot synthesis of α-aryl- and α-heteroaryl-α-trifluoromethyl alcohols carrying not only arenes with electron-withdrawing groups but also electron-deficient nitrogen-containing heteroarenes, which are of increasing interest becau
Solvolytic reactivity of heptafluorobutyrates and trifluoroacetates
Denegri, Bernard,Kronja, Olga
experimental part, p. 5927 - 5933 (2009/12/26)
(Chemical Equation Presented) A series of X,Y-substituted benzhydryl heptafluorobutyrates (1-6-HFB) and trifluoroacetates (1-6-TFA) were subjected to solvolysis in various methanol/water, ethanol/water, and acetone/water mixtures at 25°C. The LFER equation log k = sf(Ef + N f) was used to derive the nucleofuge-specific parameters (N f and sf) for SN1-type reaction. In comparison with TFA, the HFB leaving group is a better nucleofuge for less than 0.5 unit of Nf. X,Y-Substituted benzhydryl trifluoroacetates solvolyze by way of SN1 reactions unless electron-withdrawing groups are attached to aromatic rings. In such cases the substrates solvolyze faster than predicted for the SN1 route because of the change in mechanism. X,Y-Substituted benzhydryl heptafluorobutyrates examined here (Ef ≥ -7.7) solvolyze according to the SN1 pathway. The almost parallel log k vs. Ef lines in various solvents for HFBs and TFAs, and the corresponding slope parameters (sf are in the range of 0.91 and 0.83), indicate early TS with moderately advanced charge separation. NBO charges of HFB and TFA anions and the affinities obtained, all calculated at the PCM-B3LYP/6-311+G(2d,p)//PCM-B3LYP/6-311+G(2d, p) level, revealed that the HFB anion slightly better delocalizes the developing negative charge than TFA, and that the affinity of the benzhydrylium ion is slightly larger toward TFA than toward the HFB anion, which is in accordance with the greater solvolytic reactivity of HFB.
Zinc-Promoted Reactions. 1. Mechanism of the Clemmensen Reaction. Reduction of Benzophenone in Glacial Acetic Acid
Vona, Maria Luisa Di,Rosnati, Vittorio
, p. 4269 - 4273 (2007/10/02)
The mechanism of the Clemmensen reduction of diaryl ketones was investigated by reducing benzophenone, benzhydryl chloride, and dichlorodiphenylmethane in AcOH under a variety of conditions.Besides diphenylmethane, dimeric products were isolated that were indicative of the formation of radical species.Different product distributions were obtained from reactions run under different conditions.The reduction of deuteriated benzhydryl chloride was also performed.A quite complicated mechanistic pattern, involving ionic and nonionic reactions, emerged from the experimental p icture.Two pathways, connected through the protonated substrate, were recognized.According to the first pathway the reduction is promoted by a SET from Zn to the substrate, leading to the formation of a carbon radical having one zinc atom bound to the oxygen of the carbonyl group.Benzhydryl chloride, benzhydryl acetate, and dichlorodiphenylmethane are involved in the process.The product distributions suggest the occurrence of several SETs, which involve the formation of different radical species.Ionic reactions are responsible for the second route to the reduced products.Nucleophilic displacements also participate to the complex mechanism.
