Controllable Selectivity of Photosensitized Oxidation of Olefins Included in Vesicles
作者:Hong-Ru Li、Li-Zhu Wu、Chen-Ho Tung
DOI:10.1016/s0040-4020(00)00656-6
日期:2000.9
trans-stilbene and trans,trans-1,4-diphenyl-1,3-butadiene in mixed surfactantvesicles was investigated. While the oxidation in homogeneous solution yields the products derived from both the energy transfer and the electrontransfer pathways, that within vesicles selectively yields either the singlet oxygen mediated or the superoxide radical anion mediated products depending on the status and location of the substrate
Practical and Highly Selective Sulfur Ylide Mediated Asymmetric Epoxidations and Aziridinations Using an Inexpensive, Readily Available Chiral Sulfide. Applications to the Synthesis of Quinine and Quinidine
作者:Ona Illa、Muhammad Arshad、Abel Ros、Eoghan M. McGarrigle、Varinder K. Aggarwal
DOI:10.1021/ja9100276
日期:2010.2.17
one-step synthesis of a chiral sulfide which exhibits outstanding selectivities in sulfur ylide mediated asymmetric epoxidations and aziridinations. In particular reactions of benzyl and allylic sulfonium salts with both aromatic and aliphatic aldehydes gave epoxides with perfect enantioselectivities and the highest diastereoselectivities reported to date. In addition reactions with imines gave aziridines
Enantioselective Synthesis of (Thiolan-2-yl)diphenylmethanol and Its Application in Asymmetric, Catalytic Sulfur Ylide-Mediated Epoxidation
作者:Hsin-Yi Wu、Chih-Wei Chang、Rong-Jie Chein
DOI:10.1021/jo400648f
日期:2013.6.7
This work describes an expeditious and efficient preparation of enantiopure (thiolan-2-yl)diphenylmethanol (2) featuring a double nucleophilic substitution and Shi epoxidation as key steps. One of the applications of its benzyl ether derivative to asymmetric sulfur ylide-mediated epoxidation with up to 92% ee (14 examples) was also demonstrated herein.
Stereochemistry of bis-(dichlorocyclopropanation) and -(epoxidation) of 1,4-diarylbutadienes
作者:M.D. Abul Hashem、Peter Weyerstahl、Bernard S. Green
DOI:10.1016/0040-4020(84)85121-2
日期:1984.1
Dichlorocyclopropanation as well as epoxidation of the 1,4-diarylbutadienes 1-4 to give the mono- and/or bisadducts according to several hindrance of large substituents as 2,6-dichlorophenyl. The bisadducts are formed preferably as meso- (or threo-) isomers.
Enantioenriched selenonium ylides have been generated by addition of benzyl bromide to C2 symmetric (2R,5R)-2,5-dimethylselenolane in the presence of NaOH, and subsequently reacted with a variety of aldehydes to give oxiranes with excellent enantiomeric excesses (a catalytic version has been achieved); also, an aliphatic cyclic hypervalent dibromoselenurane structure has been demonstrated by X-ray analysis