Cycloadditions. 41. Conversion of unsaturated alcohols into functionalized tetrahydrofurans and tetrahydropyrans via nitrile oxide dipolar cycloadditions
<i>In situ</i> generation of nitrile oxides from copper carbene and <i>tert</i>-butyl nitrite: synthesis of fully substituted isoxazoles
作者:Rongxiang Chen、Abosede Adejoke Ogunlana、Shangwen Fang、Wenhao Long、Hongmei Sun、Xiaoguang Bao、Xiaobing Wan
DOI:10.1039/c8ob01067f
日期:——
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental
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
[EN] A SUBSTITUTED OXOPYRIDINE DERIVATIVE<br/>[FR] DÉRIVÉ D'OXOPYRIDINE SUBSTITUÉ
申请人:BAYER PHARMA AG
公开号:WO2019197244A1
公开(公告)日:2019-10-17
The invention relates to 5-(6-amino-2-[4-(5-chloro-2-cyanophenyl)-5-methoxy-2-oxopyridin-1(2/7)-yl]-3-mcthylhcxanoyl}amino)pyrazolo[1,5-c/]pyridinc-3-carboxamide, to processes for its preparation, to its use for the treatment and/or prophylaxis of diseases and to its use for the preparation of medicaments for the treatment and/or prophylaxis of diseases, in particular cardiovascular disorders, preferably thrombotic or thromboembolic disorders, and edemas, and also ophthalmic disorders, and its use to inhibit disturbing plasma kallikrein activity for the conduct of extracorporeal procedures and analytical assays.
The titled Claisen modification is shown to proceed with a remarkably high level of diastereoselection and asymmetric transmission by virtue of the proper choice of the combination of the silyl triflate and the tertiary amine used.