Regioselective monoepoxidation of 1,3-dienes catalysed by transition-metal complexes
作者:Dorte S. Thomsen、Birgit Schiøtt、Karl Anker Jørgensen
DOI:10.1039/c39920001072
日期:——
A procedure for regioselective monoepoxidation of mainly the less substituted double bond of 1,3-dienes with sodium hypochlorite or iodosylbenzene using various metal complexes as catalysts is presented; the results obtained are different from those found when applying the usual epoxidation reagents.
Synthesis and reactivity of novel π-allylcyclopentadienyl cobaltolactone complexes
作者:Steven D. R. Christie、Christophe Cosset、David R. Hamilton、William J. Kerr、John M. O'Callaghan
DOI:10.1039/c39950002051
日期:——
A range of novel cobaltolactone complexes are prepared under photolytic conditions from dicarbonylcyclopentadienylcobalt and vinyl epoxides; their subsequent reactivity under a selected series of reaction conditions is described.
Selective epoxidation of various alkenes with molecular oxygen (O2) under mild conditions is a longstanding challenge in achieving syntheses of epoxides. Cu-based catalysts have been found to be catalytically active for selective epoxidations. However, the application of copper nanoparticles (CuNPs) for photocatalyzed epoxidations is encumbered by the instability of CuNPs in air. Herein we report that
Isolation and molecular structure of unusual oxochromium(V) cations for the catalytic epoxidation of alkenes
作者:Thomas L. Siddall、Norio Miyaura、John C. Huffman、Jay K. Kochi
DOI:10.1039/c39830001185
日期:——
The first X-ray crystal structure of an oxochromium(V) complex capable of effecting oxygen atom transfer to alkenes in stoicheiometric and catalytic systems is reported.
报道了能够在化学计量和催化系统中实现氧原子转移至烯烃的氧合铬(V)配合物的第一个X射线晶体结构。
Rhodium-catalyzed regioselective opening of vinyl epoxides with Et<sub>3</sub>N·3HF reagent – formation of allylic fluorohydrins
作者:Qi Zhang、Hien M. Nguyen
DOI:10.1039/c3sc51949j
日期:——
A highly regioselective rhodium-catalyzed ring-opening of vinyl epoxides with Et3N·3HF reagent to form branched allylic fluorohydrins is described. The reaction occurs at room temperature under ambient air and relies on RhCOD2BF4 as an effective catalyst, providing the desired 1,2-addition allylic fluorohydrins in moderate to good yields with excellent levels of regioselectivity. Mechanistic studies