作者:Paul J. Kropp、Norbert J. Pienta、Joy A. Sawyer、Richard P. Polniaszek
DOI:10.1016/s0040-4020(01)92370-1
日期:——
The previously observed cyclopropaoation of alkenes by irradiation of diiodomethane (I) in their presence has been studied in more detail and found to be a synthetically useful procedure which is significantly less subject to steric effects than the traditional Simmons-Smith method. The results from photocyclopropanation of a variety of alkenes are summarized in Tables 1 and 3–4. In a number of cases
High temperature bromination Part XXIII: Bromination of octahydro-1H-indene and octahydro-1H-4,7-methanoindene
作者:Melek Sermin Ozer、Benan Kilbas、Metin Balci
DOI:10.3998/ark.5550190.p008.195
日期:——
photobromination of octahydro-1H-indene and octahydro-1H-4,7-methanoindene were investigated. Three isomeric tetrabromides (1,3,4,7-tetrabromo-2,3,4,5,6,7-hexahydro-1Hindene) were formed along with a smaller amount of tribromoindane and a pentabromide by thermal bromination of octahydro-1H-indene. The thermodynamically most stable isomers were formed. Morover, thermal and photochemical bromination of octahydro-1H-4
Computationally Guided Stereocontrol of the Combined CH Functionalization/Cope Rearrangement
作者:Yajing Lian、Kenneth I. Hardcastle、Huw M. L. Davies
DOI:10.1002/anie.201103568
日期:2011.9.26
Diastereoselectivity in control: The synthetic utility of the CH functionalization/Coperearrangementreaction has been greatly expanded by the design of substrates that will react through a boattransition state instead of a chairtransition state. The products are formed with the opposite diastereoselectivity as previously obtained (see scheme, ABSA= acetamidobenzenesulfonylazide).
Nucleophilic reactivity of the carbon-carbon double bond—V
作者:P.D. Bartlett、E.M. Nicholson、R. Owyang
DOI:10.1016/s0040-4020(01)90951-2
日期:1966.1
The acetolysis of 3-(Δ2-cyclohexenyl)propyl p-nitrobenzenesulfonate (11) is 1·64 times as fast as that of its saturated analog, the 3-cyclohexylpropyl ester; it leads to a mixture including 18·9% of bicyclic products, which consist of olefins (3 or 4) and acetate (2) in the ratio of 1·67 to 1. The product is closely related in composition to that obtained7 by acetolysis of the toluenesulfonate (14)
Aerobic Ru-Catalyzed Epoxidations in Fluorous Biphasic System Using New Fluorous Benzimidazolic Ligands
作者:Paul Knochel、Gianna Ragagnin
DOI:10.1055/s-2004-820042
日期:——
An efficient ruthenium catalyzed fluorous biphasic epoxidation of alkenes with oxygen in the presence of a pyridine-benzimidazole ligand bearing perfluorinated ponytails is described. Excellent yields and reaction rates were obtained and the fluorous phase could be recycled up to ten times without any loss of activity.