Further studies on silatropic carbonyl ene cyclisations: β-crotyl(diphenyl)silyloxy aldehyde substrates; synthesis of 2-deoxy-2-C-phenylhexoses
作者:Jeremy Robertson、Stuart P. Green、Michael J. Hall、Andrew J. Tyrrell、William P. Unsworth
DOI:10.1039/b804752a
日期:——
carbonyl ene cyclisations of beta-(allylsilyloxy)- and beta-(crotylsilyloxy)butyraldehydes are shown to proceed with high stereoselectivity but at a much reduced rate in comparison to the cyclisation of analogous alpha-substrates. In the second section, olefin cross-metathesis is explored as a route to substituted alpha-(allylsilyloxy)aldehydes and the method applied to the synthesis of diastereomeric
Silatropic Carbonyl Ene Cyclizations in the Synthesis of Pseudosugars and Hydroxylated Piperidines
作者:Jeremy Robertson、Petra M. Stafford、Stephen J. Bell
DOI:10.1021/jo050644v
日期:2005.9.1
We describe two applications of silicon-tethered thermal allyl transfer reactions of α-silyloxyaldehydes; formally, these processes can be regarded as silatropic carbonyl enereactions in which the silicon tether is transferred to the aldehyde oxygen concurrent with carbonyl allylation. In the first application, isoserinal substrates, which bear side-chain nitrogen functionality, are elaborated to
Dinitroalkyl and fluorodinitroalkyl silicon compounds
申请人:The United States of America as represented by the Secretary of the Navy
公开号:US04139403A1
公开(公告)日:1979-02-13
Energetic silicon compounds of the general formulae ##STR1## The gem dinitro compounds are prepared from alkyl bromide silanes by sod nitrite displacement and oxidative nitration. The compounds are then fluorinated. To prepare the polysiloxanes, phenyl blocking groups are used during synthesis of the fluoro dinitro moiety and are then replaced with bromine and the monomer is hydrolyzed.
Understanding the role of ring strain in β-alkyl migration at Mg and Zn centres
作者:Joseph M. Parr、Andreas Phanopoulos、Aaranjah Vickneswaran、Mark R. Crimmin
DOI:10.1039/d2sc06288g
日期:——
intramolecular C–C bond activation. While hydrometallation of methylidene cyclopropane, cyclobutane, cyclopentane and cyclohexane occurs for both Mg and Zn reagents, the C–C bond activation step is sensitive to ring size. For Mg, both cyclopropane and cyclobutane rings participate in C–C bond activation. For Zn, only the smallest cyclopropanering reacts. These findings were used to expand the scope of catalytic