Hydroformylation of 1,4-diolefins in the presence of primary amines leading to heterocyclic compounds
作者:Christian L. Kranemann、Beate E. Kitsos-Rzychon、Peter Eilbracht
DOI:10.1016/s0040-4020(99)00162-3
日期:1999.4
The Rh(I)-catalysed hydroformylation of dienes in the presence of amines is applied to heterocyclic ring synthesis. Starting from 1,4-dienes pyrroles or eight-memberedheterocycles are easily accessible. The selectivity of the reaction is controlled by the substitution pattern of the diolefin.
Gallium-mediated allyl transfer from bulky homoallyl alcohol to aldehydes or alkynes: Control of dynamic σ-allylgalliums based on retro-allylation reaction
reagent and gallium trichloride, bulky homoallylalcohols undergo gallium-mediated retro-allylation reaction to provide σ-allylgallium reagents. The σ-allylgallium reagents generated were applied to carbonyl allylation. The retro-allylation reaction generates (Z)- and (E)-σ-crotylgalliums stereospecifically, starting from erythro- and threo-homoallyl alcohols, respectively. The stereochemically defined
Synthesis of Cyclic Peroxides by Chemo- and Regioselective Peroxidation of Dienes with Co(II)/O<sub>2</sub>/Et<sub>3</sub>SiH
作者:Takahiro Tokuyasu、Shigeki Kunikawa、Kevin J. McCullough、Araki Masuyama、Masatomo Nojima
DOI:10.1021/jo048359j
日期:2005.1.1
Consistent with results from simple alkenes, the chemo- and regioselective peroxidation of dienes was also realized. Depending on the diene structure, the product included not only the expected acyclic unsaturated triethylsilyl peroxides but also 1,2-dioxolane and 1,2-dioxane derivatives via intramolecularcyclization of the unsaturated peroxy radical intermediates.
在两种烯烃与 Co(II)/O 2 /Et 3 SiH的混合物的竞争性过氧化反应中,发现烯烃底物的相对反应性受三个主要因素的影响:(1) 烯烃与 HCo(III) 络合物反应形成的中间碳中心自由基的相对稳定性,(2) C C 双键周围的空间效应,以及 (3) 与 C 相关的电子因素C 双键。与简单烯烃的结果一致,还实现了二烯的化学和区域选择性过氧化。根据二烯结构,产物不仅包括预期的无环不饱和三乙基甲硅烷基过氧化物,还包括 1,2-二氧戊环和 1,2-二氧六环衍生物,通过不饱和过氧自由基中间体的分子内环化。