A practical and efficient microwave-assistedsolid-phase method for the synthesis of N,N′-linked oligoureas and related amide/urea hybrid oligomers, featuring the use of succinimidyl (2-azido-2-substituted ethyl) carbamate monomers, is reported. The rate enhancement of urea formation under microwave irradiation combined with the mild conditions of the phosphine-based azide reduction makes this approach
The present invention relates to novel N-(2,2-difluoroehtyl)-N-[(Pyrimidinylamino)propanyl]- arylcarboxamide derivatives, processes for their preparation, pharmaceutical compositions containing them and their use in therapy, particularly in the treatment or prevention of conditions having an association with the orexin sub-type 1 receptor.
New substituted heterocyclic compounds, compositions containing them, and methods of using them for the inhibition of Raf kinase activity are provided. The new compounds and compositions may be used either alone or in combination with at least one additional agent for the treatment of a Raf kinase mediated disorder, such as cancer.
Synthesis of imidacloprid derivatives with a chiral alkylated imidazolidine ring and evaluation of their insecticidal activity and affinity to the nicotinic acetylcholine receptor
imidazolidine ring were asymmetrically synthesized to evaluate their insecticidalactivity against adult female housefly, Musca domestica, and affinity to the nicotinicacetylcholinereceptor of the flies. The bulkier the alkyl group, the lower was the receptor affinity, but the derivatives methylated and ethylated at the R-5-position of the imidazolidine ring were equipotent to the unsubstituted compound. Quantitative
Asymmetric α-Hydroxylation of a Lactone with Vinylogous Pyridone by Using a Guanidine-Urea Bifunctional Organocatalyst: Catalytic Enantioselective Synthesis of a Key Intermediate for (20<i>S</i>)-Camptothecin Analogues
We have developed a catalytic asymmetricsynthesis of (S)‐4‐ethyl‐6,6‐(ethylenedioxy)‐7,8‐dihydro‐4‐hydroxy‐1H‐pyrano[3,4‐f]indolizine‐3,10(4H)dione (5 a), a synthetic intermediate for (20S)‐camptothecin analogues. A key step in this synthesis is an asymmetric α‐hydroxylation of a lactone with a vinylogous pyridone structure (8 a) by using a guanidine–urea bifunctional organocatalyst. The present oxidation
我们开发了(S)-4-乙基-6,6-(乙二氧基)-7,8-二氢-4-羟基-1 H-吡喃[3,4- f ]吲哚嗪-3,10的催化不对称合成(4 H)二酮(5 a),是(20 S)-喜树碱类似物的合成中间体。该合成的关键步骤是使用胍-脲双功能有机催化剂使具有乙烯基吡啶酮结构(8 a)的内酯不对称α-羟基化。本发明的氧化成功地应用于(+)的C20修饰的衍生物的合成- C20-desethylbenzylcamptothecin(13)。