An efficient synthesis of bridged-bicyclic peroxides structurally related to antimalarial yingzhaosu A based on radical co-oxygenation of thiols and monoterpenes
作者:Edward E Korshin、Roland Hoos、Alex M Szpilman、Leonid Konstantinovski、Gary H Posner、Mario D Bachi
DOI:10.1016/s0040-4020(02)00126-6
日期:2002.3
Synthesis of β-sulfenyl endoperoxides 9 was achieved by a four component sequential free radical reaction based on the application of the thiol-olefin-co-oxygenation reaction to monoterpenes, followed by in situ treatment with triphenylphosphine. β-Sulfenyl endoperoxides 9 were oxidized with m-CPBA to β-sulfonyl endoperoxides 10. This process provides an efficient method for the preparation of peroxides
Cross-Coupling Reactions of Hypervalent Siloxane Derivatives: An Alternative to Stille and Suzuki Couplings
作者:Molly E. Mowery、Philip DeShong
DOI:10.1021/jo982463h
日期:1999.3.1
Palladium-catalyzed cross-coupling of phenyl, vinyl, and allyl siloxane derivatives proceeded in good to excellent yield with aryliodides, electron-deficient arylbromides, and allylic benzoates. Methyl and 2,2,2-trifluoroethyl siloxane derivatives can be employed in the couplingreaction. Electron-donating and -withdrawing groups are tolerated on the aryl halide without affecting the coupling. The
Thiol-Oxygen Cooxidation of Monoterpenes. Synthesis of Endoperoxides Structurally Related to Antimalarial Yingzhaosu A
作者:Mario D. Bachi、Edward E. Korshin
DOI:10.1055/s-1998-1587
日期:1998.2
3-dioxabicyclo[3.3.1]nonan-8-ols. A variety of cyclic peroxides have been studied as potential candidates for the treatment of malaria caused by chloroquine-resistant parasites.1 Our attention has been given to yingzhaosu A (1) and to arteflene (2), two endoperoxides characterized by a 2,3-dioxabicyclo[3.3.1]nonane system as a central molecular feature (Figure 1). Yingzhaosu A was isolated from an extract of Artabotris
Bimetallic Radical Redox-Relay Catalysis for the Isomerization of Epoxides to Allylic Alcohols
作者:Ke-Yin Ye、Terry MCallum、Song Lin
DOI:10.1021/jacs.9b04993
日期:2019.6.19
exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely, bimetallic radical redox-relay, in the regio- and stereoselectiverearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti
有机自由基通常是具有异常高反应性的短寿命中间体。从战略上讲,实现由有机自由基介导的合成有用的转化需要有效的引发和选择性终止事件。在这里,我们报告了一种新的催化策略,即双金属自由基氧化还原继电器,用于环氧化物向烯丙醇的区域和立体选择性重排。这种方法利用了 Ti 和 Co 配合物的丰富氧化还原化学,并将还原性环氧化物开环(引发)与氢原子转移(终止)相结合。至关重要的是,在影响关键的成键和断裂事件时,Ti 和 Co 催化剂彼此进行质子转移/电子转移以实现周转,从而构成真正协同的双催化系统。
Hypervalent silane and siloxane derivatives and the use thereof
申请人:University of Maryland
公开号:US06414173B1
公开(公告)日:2002-07-02
Hypervalent silane and siloxane reagents (preformed or generated in situ) for transmetalation in palladium catalyzed reactions with derivatives of allylic alcohols, aryl halides, electron-withdrawing aryl bromides, and aryl triflates derived from phenols are disclosed. Also disclosed are methods of preparing glycosyl azides by reaction of an azide with a silyl ester in the presence of a phoshine.