[EN] DIRECT STEREOSPECIFIC SYNTHESIS OF UNPROTECTED AZIRIDINES FROM OLEFINS [FR] SYNTHÈSE STÉRÉOSPÉCIFIQUE DIRECTE D'AZIRIDINES NON PROTÉGÉES À PARTIR D'OLÉFINES
Direct <i>N</i>-H/<i>N</i>-Me Aziridination of Unactivated Olefins Using <i>O</i>-(Sulfonyl)hydroxylamines as Aminating Agents
作者:Shekh Sabir、Chandra Bhan Pandey、Ajay K. Yadav、Bhoopendra Tiwari、Jawahar L. Jat
DOI:10.1021/acs.joc.8b01673
日期:2018.10.5
methods are devoted to their activated counterparts. Herein, we have developed a highly efficient Rh(II)-catalyzed method for the direct preparation of unactivated aziridines from olefins using O-(sulfonyl)hydroxylamines as the aminating agent. The reactions proceed with a high stereospecificity.
The stereospecific, substrate (nitrogen source)-controlled intermolecular anti- and syn-1,2-diaminations of unactivated alkenes using the same catalysis (an iodine catalyst) is reported. The combined use of the two potential methods provides access to all of the disastereomeric forms of 1,2-diamines in spite of the availability of E- and Z-alkenes, and the resulting products can be readily converted
Dirhodium(II)-Mediated Alkene Epoxidation with Iodine(III) Oxidants
作者:Ali Nasrallah、Gwendal Grelier、Maria Ivana Lapuh、Fernando J. Duran、Benjamin Darses、Philippe Dauban
DOI:10.1002/ejoc.201800306
日期:2018.11.15
combination of the dirhodium(II) complex Rh2(tpa)4 (tpa = triphenylacetate) with the iodine(III) oxidant PhI(OPiv)2 is shown to promote the epoxidation of alkenes in the presence of 2 equivalents of water. The reaction can be applied to diversely substituted alkenes and the corresponding epoxides are isolated with yields of up to 90 %. A possible mechanism involves the dirhodium(II) complex as a Lewis
Dirhodium (II) 络合物和碘 (III) 氧化剂已在合成氮烯化学中找到有用的应用。在这项研究中,二铑(II)配合物 Rh2(tpa)4(tpa = 三苯乙酸盐)与碘(III)氧化剂 PhI(OPiv)2 的组合被证明在 2 当量的水。该反应可应用于不同取代的烯烃,并以高达 90% 的产率分离相应的环氧化物。一种可能的机制涉及二铑 (II) 络合物作为路易斯酸物质,它可以调节碘 (III) 试剂的氧化特性。
Silyl methallylsulfinates: efficient and powerful agents for the chemoselective silylation of alcohols, polyols, phenols and carboxylic acids
Alcohols, phenols and carboxylic acids are silylated with very good yields in the presence of silyl methallylsulfinates under non-basic conditions and with the formation of volatile co-products.
Distal Allylic/Benzylic C−H Functionalization of Silyl Ethers Using Donor/Acceptor Rhodium(II) Carbenes
作者:Janakiram Vaitla、Yannick T. Boni、Huw M. L. Davies
DOI:10.1002/anie.201916530
日期:2020.5.4
achieved usingrhodium(II) carbenes derived from N-sulfonyltriazoles and aryldiazoacetates as carbene precursors. The bulky rhodium carbenes led to highly site-selective functionalization of less activated allylic and benzylic C-H bonds even in the presence of electronically preferred C-H bonds located α to oxygen. The dirhodium catalyst Rh2 (S-NTTL)4 is the most effective chiralcatalyst for triazole-derived