Oxygen transfer reactions from an Oxaziridinium tetrafluoroborate salt to Olefins
作者:Xavier Lusinchi、Gilles Hanquet
DOI:10.1016/s0040-4020(97)00890-9
日期:1997.10
Oxaziridinium efficiently epoxidises olefins. It reacts as an electrophilic reagent and does not transfer its oxygen to deactivated double-bonds or carbonyl functions. Epoxidation of cyclic allylic acetates shows a remarkable diastereoselectivity leading to the syn isomer. We propose that the epoxidation reaction proceeds through a one-step process.
Stereo- and regioselectivity in the P450-catalyzed oxidative tandem difunctionalization of 1-methylcyclohexene
作者:Gheorghe-Doru Roiban、Rubén Agudo、Manfred T. Reetz
DOI:10.1016/j.tet.2013.04.132
日期:2013.7
non-functionalized molecules using biocatalysis based on P450 monooxygenases is known to be difficult due to the expected poor regio- and stereoselectivity, but in this study it was nevertheless attempted. 1-Methylcyclohexene was subjected to oxygen-mediated biocatalytic oxidation using P450-BM3 as the catalyst. Both oxidative hydroxylation and epoxidation were observed, in some cases leading to hydroxy epoxides with
Domino Reactions Consisting of Heterocyclization and 1,2-Migration-Redox-Neutral and Oxidative Transition-Metal Catalysis
作者:Klaus-Daniel Umland、Adeline Palisse、Timm T. Haug、Stefan F. Kirsch
DOI:10.1002/anie.201103961
日期:2011.10.10
paths: Two novel dominoreactions starting from 6‐hydroxy‐2‐alkyl‐2‐alkynylcyclohexanones have been discovered. While redox‐neutral platinum catalysis gives rise to furans through a sequence of cyclization, 1,2‐shift, and Grob fragmentation, oxidative copper catalysis provides an entry to bicyclic 2,3‐dihydrofurans. Upon cyclization and oxidation, an unusual benzilic acidrearrangement can take place
Diastereoselective epoxidation of allylically substituted alkenes using metalloporphyrin catalysts
申请人:Che Chi-Ming
公开号:US20050209470A1
公开(公告)日:2005-09-22
Diastereoselective epoxidation of allylically substituted alkenes using metalloporphyrins as catalyst provides high trans-selectivities (i.e., trans-:cis-epoxide ratio). A diversity of cycloalkenes bearing different allylic substituents are shown to be efficiently epoxidized to afford the corresponding trans-epoxides with excellent trans-selectivities (up to >98%) and good yields (up to 99%). Acyclic allylic alkenes bearing different allylic substituents are efficiently epoxidized to afford the corresponding erythro-epoxides with good erythro-selectivities. The metalloporphyrin-catalyzed reactions exhibit up to 20 times higher trans-selectivities than the conventional method using m-chloroperoxybenzoic acid as oxidant.
Facile and Efficient Synthesis of Lactols by a Domino Reaction of 2,3-Epoxy Alcohols with a Hypervalent Iodine(III) Reagent and Its Application to the Synthesis of Lactones and the Asymmetric Synthesis of (+)-Tanikolide
作者:Hiromichi Fujioka、Satoshi Matsuda、Mai Horai、Eri Fujii、Maiko Morishita、Natsuko Nishiguchi、Kayoko Hata、Yasuyuki Kita
DOI:10.1002/chem.200601341
日期:2007.6.15
The dominoreaction of 2,3-epoxy-1-alcohol derivatives, namely tetrasubstituted 2,3-epoxy-1-alcohols and 2- or 3-alkyl trisubstituted 2,3-epoxy-1-alcohols, with PhI(OCOCF(3))(2) in the presence of H(2)O is described in detail. In this reaction, several types of lactol derivatives can be directly obtained from the 2,3-epoxy-1-alcohol derivatives in a single operation. The obtained lactols were successively