Use of a Semihollow-Shaped Triethynylphosphane Ligand for Efficient Formation of Six- and Seven-Membered Ring Ethers through Gold(I)-Catalyzed Cyclization of Hydroxy-Tethered Propargylic Esters
The formation of six‐ and seven‐membered ring ethers from hydroxy‐tethered propargylic esters was efficientlycatalyzed by a cationic gold(I) complex with a semihollow‐shaped triethynylphosphane ligand. This gold catalysis showed a tolerance toward the reactions of primary, secondary, and tertiary alcohol substrates with various substitution patterns. A sterically congested 2,2,6,6‐tetraalkyl‐substituted
Synthesis of sub-units of marine polycyclic ethers by ring-closing metathesis and hydroboration of enol ethers
作者:J. Stephen Clark、Jason G. Kettle
DOI:10.1016/s0040-4020(99)00303-8
日期:1999.7
The construction of polycyclicethers by sequential ring-closing metathesis and stereoselective hydroboration of enol ethers has been explored. This reaction sequence has been used to prepare bicyclic ethers corresponding to sub-units found in the brevetoxins and related marine natural products.
A stereoselective synthesis of tri-substituted alkenes. The nickel-catalysed coupling of Grignard reagents with 6-alkyl-3,4-dihydro-2H-pyrans.
作者:Philip Kocieński、Nicholas J. Dixon、Sjoerd Wadman
DOI:10.1016/s0040-4039(00)86058-x
日期:1988.1
6-alkyl-3,4-dihydro-2H-pyrans is highly stereoselective and gives tri-substituted alkenes with retention of configuration. The method was applied to the synthesis of (E)-3-Acetoxy-7-methyl-6-nonene, the aggregation phermone of the square-neckedgrainbeetle.
A highly diastereo- and enantioselective [3 + 2] cycloaddition of 2,2′-diester aziridines with 3,4-dihydropyran derivatives and acyclic enolethers has been established. Various optically active octahydropyrano[2,3-c]pyrrole and 3-methoxypyrrolidine derivatives were generated in moderate to high yields (up to 94%) and good stereoselectivities (>19:1 dr, up to 95.5:4.5 er). The methodology was also
已经建立了2,2'-二酯氮丙啶与3,4-二氢吡喃衍生物和非环烯醇醚的高度非对映和对映选择性[3 + 2]环加成反应。以中等至高产率(高达94%)和良好的立体选择性(> 19:1 dr,高达95.5:4.5 er)生成了各种旋光的八氢吡喃并[2,3- c ]吡咯和3-甲氧基吡咯烷衍生物。该方法还用于d-半乳糖衍生物的高度非对映选择性合成中。八氢吡喃并[2,3- c ]吡咯的绝对构型表明,在最后的环化步骤中,使用3,4-二氢吡喃和6-烷基取代的吡咯为底物的反应给出了反向的非对映异构。