12152-59-9

Upstream product

• 598-73-2 1-bromo-1,2,2-trifluoroethene 
• 79-38-9 Chlorotrifluoroethylene 

Relevant academic research and scientific papers

A new mechanism of nucleophilic vinylic substitution and unexpected products in the reaction of chlorotrifluoroethylene with [Re(CO)5]Na and [CpFe(CO)2]K

The mechanism of chloride substitution in CF2{double bond, long}CFCl with [Re(CO)5]- and [CpFe(CO)2]- anions is investigated experimentally and theoretically. The substitution reaction begins with the nucleophile addition to CF2{double bond, long}CFCl producing the carbenoid anion [MCF2CFCl]- (A) (M = Re(CO)5, CpFe(CO)2). This is shown by trapping the intermediate A with electrophiles - proton donor (t-BuOH) to give MCF2CFClH or with CF2{double bond, long}CFRe(CO)5 to give acylmetallate III, and by the formation of the substitution products CF2{double bond, long}CFM from the anion A, generated by the deprotonation of MCF2CFClH with t-BuOK. 1,2-Shift of metal carbonyl group concerted with the α-elimination of chloride anion is proposed as the transformation pathway of carbenoid A into CF2{double bond, long}CFM. A competing process of carbene insertion into Fe-C{triple bond, long}O bond is proposed to explain the formation of {A figure is presented} (XI). The feasibility of these two pathways is confirmed by DFT (B3LYP/SDD and 6-31G*) calculations of the carbenes [MCF2CF:] and carbenoid anions [MCF2CFCl]-. Transition states (TS) for 1,2-shift (+3.2 kcal/mol) and for nucleophilic addition at C{triple bond, long}O ligand (+5.4 kcal/mol) are located for [(CO)5ReCF2CFCl]-, but only one TS corresponding to carbene insertion into Fe-C{triple bond, long}O bond (+2.1 kcal/mol) is located for [(CO)2CpFeCF2CFCl]-. The formation of other newly observed products, F(CO)CHFRe(CO)5 (V) and Cp(CO)2FeC{triple bond, long}CFeCp(CO)2 (VIII) is also discussed.

Nucleophilic vinylic substitution with transition metal carbonyl anions - A rare case of a halophilic reaction mechanism. Formation of halo(acyl)rhenate complexes and X-ray structure of cis-[CF2=CF(CO)Re(CO)4Br]Na

Reactions of polyfluorinated alkenyl halides Z-(CF3) 3CCF=6;CFHal (Hal=Cl,I-Cl, Hal=Br, I-Br) and CF2=CFBr (II-Br) with [CpFe(CO)2]K (FpK) and [Re(CO)5]Na proceed through the initial attack of metal carbonyl anion on halogen. Reaction with FpK gives minor amounts of σ-alkenyl complexes Z-RfCF=CFFe(CO)2Cp (I-Fe, II-Fe) (3-30%), but primarily leads to dimer [CpFe(CO)2] 2. Reaction with [Re(CO)5]Na produces anionic halo(acyl)rhenates cis-[Z-RfCF=CF(CO)Re(CO)4Hal]Na (V-Cl, V-Br, VI) (70-90%) which were isolated, and halo(acyl)rhenate VI (Rf=F) was characterized by X-ray structure analysis. Halo(acyl)rhenates result from the attack of the intermediate carbanion [RfCF=CF]- on the carbonyl ligand of Re(CO) 5Hal. The involvement of [RfCF=CF]- is demonstrated by their trapping with t-BuOH or CH-acid, which gives the protodehalogenated alkenes I-H and II-H, and suppresses the nucleophilic substitution reaction leading to I-Fe, II-Fe or V-Cl. Arguments against a radical/SET mechanism for the substitution reaction are also advanced.