The intramolecularcyclopropanation of various trans-allylic diazoacetates and alkenyl diazoketones has been achieved with excellent enantioselectivities of up to 98% ee and in quantitative yields by using a water-solubleruthenium(II)/hydroxymethyl(phenyl)oxazoline catalyst in a water/ether biphasic medium. The catalyst could be reused at least five times.
A versatile building block for the synthesis of substituted cyclopropanephosphonic acid esters
作者:László Töke、Zsuzsa M. Jászay、Imre Petneházy、György Clementis、Györgyi D. Vereczkey、István Kövesdi、Antal Rockenbauer、Katalin Kováts
DOI:10.1016/0040-4020(95)00522-a
日期:1995.8
By the effect of iodine, solid K2CO3 and a lipophilic quaternary ammonium salt phosphonoacetic acid allylic esters 4 were converted to cyclopropanephosphonic acid derivatives anellated to a five membered lactone ring 6 serving as good starting material for biologically active products. The reaction of cyclopropanation has been assumed to proceed by SET induced radical type elemental steps. Direct evidences
通过碘的作用,固体K 2 CO 3和亲脂性季铵盐膦酰基乙酸烯丙基酯4被转化为环丙烷膦酸衍生物,其被芳香化为五元内酯环6,作为生物活性产物的良好起始原料。已假定环丙烷化反应是通过SET诱导的自由基型元素步骤进行的。由ESR提供的直接证据表明,亲电基团11的封闭有6个内基的区域选择性。还观察到了膦酸酯部分与碘的有趣且新的交换反应。
Intramolecular Cyclopropanation of Bromodiazoacetates
series of allylicdiazoacetates were prepared from the corresponding allylic alcohols and bromoacetyl bromide. When the allylicdiazoacetates were treated with 1,8-diazabicyclo[5.4.0]undec-7-ene and N-bromosuccinimide, a rapid full conversion to the corresponding allylic bromodiazoacetates occurred. Exposure of the allylic bromodiazoacetates to rhodium(II) catalysts induced an intramolecular cyclopropanation
由相应的烯丙醇和溴乙酰溴制备了一系列烯丙重氮乙酸酯。当烯丙基重氮乙酸酯用 1,8-二氮杂双环 [5.4.0] undec-7-ene 和 N-溴代琥珀酰亚胺处理时,迅速完全转化为相应的烯丙基溴重氮乙酸酯。烯丙基溴重氮乙酸盐暴露于铑 (II) 催化剂会诱导分子内环丙烷化,并产生环丙基溴内酯的产率从低到高取决于取代模式。
Photocatalytic Generation of π-Allyltitanium Complexes from Butadiene via a Radical Strategy
作者:Fusheng Li、Shuangjie Lin、Lei Shi、Xiyu Li
DOI:10.1055/s-0040-1706024
日期:2021.6
is of great appeal to the synthetic community as well as industrial applications. This study reports a conceptually new radical strategy for the photocatalytic generation of π-allyltitanium complexesfrombutadiene. This novel and environmentally benign strategy enables the direct three-component allylation of carbonyls with 1,3-butadiene and α-bromocarboxylates, providing rapid access to valuable homoallylic
The invention provides a resist composition comprising a polymer (a) having groups cleavable by an acid and a compound (b) which can form an acid upon exposure to active rays, wherein the polymer (a) is a polymer having, as the groups cleavable by an acid, groups containing a substituted allyloxy group having at least two substituents, and a resist composition comprising a resin binder (A), a compound (B) which can form an acid upon exposure to active rays, and a compound (C) having a group cleavable by an acid, wherein the compound (C) having the group cleavable by an acid is a compound having a group containing a substituted allyloxy group having at least one substituent. The resist compositions have excellent sensitivity, resolution and heat resistance and can provide excellent pattern form.