Synthesis of tetrasubstituted cyclopropenes and medium to large carbocyclic alkenes by the intramolecular reductive coupling of diketones with titanium trichloride-lithium aluminum hydride
Radical hydroformylation and hydrogenation of cyclopropenes with HCo(CO)4 and HMn(CO)5
作者:Theodore E. Nalesnik、John H. Freudenberger、Milton Orchin
DOI:10.1016/s0022-328x(00)86753-4
日期:1982.9
The results of a study of the reactions of HCo(CO)4 and HMn(CO)5 with a variety of a substituted cyclopropenes are consistent with the formation of the intermediate caged radical pairs; recombination in the cage of the radical pair leads to hydroformylation, and cage escape leads to hydrogenation. Steric factors play an important role in determining rates as well as the stereochemistry of the products
Olefin reactions with HMn(CO)5: Product selectivity by micelle sequestering
作者:Yasushi Matsui、Milton Orchin
DOI:10.1016/0022-328x(83)80045-x
日期:1983.3
The reaction of HMn(CO)5 with certain cyclopropenes when carried out in a detergent medium gives a different mixture of hydroformylated and hydrogenated products than is obtained when the same reaction is carried out in a homogeneous medium. These results are consistent with the intermediacy of caged geminate radical pairs whose escape from the cage is retarded by micelle sequestering.
We report here the first example of a stoichiometric hydroformylation using HMn(CO)5. Treatment of a hexane solution of 1,2-diphenyl-3,3-dimethylcyclopropene with HMn(CO)5 at 55°C gave after 5 h a 27% yield of aldehydes, 87% cis and 13% trans. The other major products were cis-(87%)-, and trans-(13%)-1,2-diphenyl-3,3-dimethylcyclopropane. Evidence for a radical intermediate is presented.
Photoinduced Electron Transfer Reactions of 3,3-Dialkylated 4,5-Diphenyl-3H-Pyrazoles: A New Route to the Formation of the Solvent Adducts
作者:Yao-Pin Yen、Tseng-Min Huang、Yu-Ping Tseng、Hsuan-Yu Lin、Ching-Cheng Lai
DOI:10.1002/jccs.200400061
日期:2004.4
3,3-Dialkyl-4,5-diphenyl-3H-pyrazoles undergo readily photoinducedelectrontransfer (PET) reaction with 2,4,6-triphenylpyrylium tetrafluoroborate (TPP + ) in acetonitrile to produce cyclopropenes and 2H-pyrroles. During prolonged irradiation, the new ring-closure products derived from 2H-pyrroles as the secondary photoproducts are also produced. However, the corresponding ester analog exhibits different