566-88-1Relevant articles and documents
Direct organocatalytic stereoselective transfer hydrogenation of conjugated olefins of steroids
Ramachary, Dhevalapally B.,Sakthidevi, Rajasekar,Reddy, P. Srinivasa
, p. 13497 - 13506 (2013/09/02)
Kinetically controlled and organocatalytic syn-selective transfer hydrogenation has been successfully demonstrated for the reduction of the enone functional group of various steroids. Herein, diastereoselective synthesis of many 5β-steroids have been reported through organocatalysis, which have broad medicinal and pharmaceutical applications. The mechanistic studies and the selectivity of the products clearly indicated that the catalyst 1b·d-CSA is mild enough to activate the various chiral cyclic enones through iminium ion formation during the organocatalytic transfer hydrogenations with Hantzsch ester 2a as a hydrogen source. Further, clear evidence for the selective formation of intermediate iminium species [I]+ have been characterized through on-line monitoring of controlled experiments by NMR and ESI-HRMS analyses.
Application of the excited state meta effect in photolabile protecting group design
Wang, Pengfei,Hu, Ayou,Wang, Yun
, p. 2831 - 2833 (2008/02/07)
A novel photolabile protecting group for carbonyl compounds has been developed, based on the excited state meta effect.
Controlling the reactive state through cation binding: Photochemistry of enones within zeolites
Uppili, Sundararajan,Takagi, Shinsuke,Sunoj,Lakshminarasimhan,Chandrasekhar,Ramamurthy
, p. 2079 - 2083 (2007/10/03)
The nature of the lowest triplet state of enones is altered by the cations present within Y zeolites. Alkali metal ions, such as Li+, are predicted to interact with the carbonyl unit of enones in a collinear fashion and significantly lower both the p-type n and π-2 orbitals. Excited state energies, estimated at the CIS(D)/6-31+G* level, show that the lowest triplet is n-π* in character for the enones, but switch to π-π* on coordination with Li+. Observed product distribution within zeolite is consistent with this theoretical prediction.
