Synthesis of allenic diols by samarium diiodide-promoted coupling between alkynyloxiranes and ketones
作者:JoséM. Aurrecoechea、Eva Alonso、Mónica Solay
DOI:10.1016/s0040-4020(98)00110-0
日期:1998.4
The SmI2-mediated reductive coupling between alkynyloxiranes and ketones provides a new route to 2,3-pentadiene-1,5-diols. The preferred stereochemistry observed in the coupling products is the result of the new CC bond forming anti with respect to the opening epoxide ring. Yields and diastereoselectivities are dependent on the alkynyloxirane substitution pattern.
Enantioselective Construction of Carbobicyclic Scaffolds
作者:Douglass F. Taber、Yigang He、Ming Xu
DOI:10.1021/ja045849k
日期:2004.11.1
Allylic and benzylic Grignard reagents smoothly open phenylalkynyl-activated cyclic trisubstituted epoxides at the more substitutedcarbon atom to give secondary alcohols with a chiral quaternarycenter. These alcohols are good substrates for the construction of enantiomerically pure carbobicyclic scaffolds through intramolecular alkylation.
<b>Asymmetric Epoxidation of Alkenes Catalyzed by a Cobalt Complex</b>
作者:Qianwen He、Mao-Ping Pu、Zheng Jiang、Hongyu Wang、Xiaoming Feng、Xiaohua Liu
DOI:10.1021/jacs.3c05476
日期:2023.7.19
Asymmetric epoxidation of alkenes catalyzed by nonheme chiral Mn–O and Fe–O catalysts has been well established, but chiral Co–O catalysts for the purpose remain virtually undeveloped due to the oxo wall. Herein is first reported a chiral cobaltcomplex to realize the enantioselective epoxidation of cyclic and acyclic trisubstituted alkenes by using PhIO as the oxidant in acetone, wherein the tetra-oxygen-based
Stereoselective samarium diiodide-promoted intermolecular coupling of alkynyloxiranes with ketones. synthesis of 2,3-pentadiene-1,5-diols
作者:JoséM. Aurrecoechea、Mónica Solay
DOI:10.1016/0040-4039(95)00254-a
日期:1995.4
In the presence of samarium diiodide (SmI2), alkynyloxiranes undergo an efficient reductive coupling with ketones to afford 2,3-pentadiene-1,5-diols. The isolated yields are high and the stereoselectivity of the process ranges from moderate to very high. The stereochemistry of the major product of the reaction is the result of the new CC bond forming anti with respect to the opening epoxide ring.
(Z)-Phenol-substituted alkenes were produced by the palladium(0)-catalyzed reaction of propargylic oxiranes with phenols. The regio- and stereoselective addition of phenols to alkynes occurs via the formation of p-propargyl- and p-allylpalladium complexes. The phenoxy-substituted enones were produced simultaneously depending on the reaction conditions. 2005 Elsevier Ltd. All rights reserved.