Inter- and intramolecular insertion of rhenium into carbon-hydrogen bonds

Journal Article · Wed Aug 06 04:00:00 EDT 1986 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00276a025· OSTI ID:5391115

Wenzel, T T; Bergman, R G

CpRe(PMe/sub 3/)/sub 3/ (1) was synthesized in 38% yield by Na/Hg reduction of ReCl/sub 3/(PMe/sub 3/)/sub 3/ (3) with cyclopentadiene. UV irradiation of 1 in benzene and cyclopropane liberated PMe/sub 3/ and gave in respective C-H insertion products Cp-(PMe/sub 3/)/sub 2/Re(Ph)H (4, 64%) and Cp(PMe/sub 3/)/sub 2/Re(c-C/sub 3/H/sub 5/)H (5, 38%). Irradiation of 1 in n-hexane or cyclopentane provided Cp(PMe/sub 3/)/sub 2/Re(n-C/sub 6/H/sub 13/)H (8, 15%) and Cp(PMe/sub 3/)/sub 2/Re(c-C/sub 5/H/sub 9/)H (9, 17%) but only at less than -30/sup 0/. Irradiation of 1 at 5-10/sup 0/C in cyclohexane afforded cyclometalated product Cp(PMe/sub 3/)Re(eta/sup 2/-CH/sub 2/PMe/sub 2/)H (10, 31%) and Cp(PMe/sub 3/)/sub 2/Re(eta/sup 1/-CH/sub 2/PMe/sub 2/)H (11, 14%). 10 can dimerize to 16 and 17. The structure of 16 was determined by X-ray crystallography. Irradiation of 1, or thermolysis (20/sup 0/C) of 10 in cyclohexane with methane gave Cp(PMe/sub 3/)/sub 2/Re(Me)H (12, 43%). Irradiation of 1 with ethylene in cyclohexane gave Cp(PMe/sub 3/)/sub 2/Re(CH=CH/sub 2/)H (14), which isomerized quantitatively to Cp-(PMe/sub 3/)/sub 2/Re(eta/sup 2/-(CH/sub 2/=CH/sub 2/)) (15, 45%) at 20/sup 0/C in benzene. Irradiation of 15 regenerated 14, regardless of solvent. Thermolysis (20/sup 0/C) of 8 with ethylene gave almost exclusively 14, thus ruling out 15 as the intermediate in the formation of 14. Isolation of compounds, 1, 5, 8, 10, 12, 15, and 16 in pure form required air-free chromatography at ca. -110/sup 0/C. An efficient synthesis of Cp(PMe/sub 3/)/sub 2/ReH/sub 2/ (6, 71% from 3) is reported. Deprotonation of 6 followed by methylation afforded 12 (72%). All of the alkane C-H insertion products undergo facile reductive elimination of RH at room temperature.

• Research Organization: Univ. of California, Berkeley, CA
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5391115
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Journal Issue: 16 Vol. 108:16; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400500 -- Photochemistry
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
DATA
DECOMPOSITION
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
ISOMERIZATION
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOSPHINES
PHOSPHORUS COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
REACTION INTERMEDIATES
RHENIUM COMPLEXES
SCATTERING
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
X-RAY DIFFRACTION
YIELDS