ISSN:
0009-2940
Keywords:
Titanium enolate
;
Cyclic voltammetry
;
EPR spectroscopy
;
Radical ion
;
Mesolytic bond cleavage
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
For the first time titanium enolate radical cations were characterized in cyclic voltammetry experiments. Preparative one-electron oxidation of titanium enolates 1-3 led to the formation of benzofurans B1-B3 through mesolytic Ti-O bond fragmentation to α-carbonyl radical and a cationic titanocene(IV) species. With 1+·, the kinetics of the Ti-=O bond cleavage was investigated by fast scan cyclic voltammetry providing a first-order rate constant k1=850 ± 50 s-1 in acetonitrile at room temperature. The titanium enolate radical cations 1+·, 3+·, 4+· and 5%% were characterized by EPR spectroscopy, qualifying these species as electrophilic radicals. This feature can be exploited in C—C bond formation reactions such as the formal dimerization of 6 to 2,3-dimethyl-1,4-diphenylbuta-1,4-dione D6, which takes place on stage of the radical cation 6+·.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19971300616
