Cyclic Diacylcarbene Generated from Iodonium Ylides and Diazodiketones
作者:Yosio Hayasi、Taiiti Okada、Mituyosi Kawanisi
DOI:10.1246/bcsj.43.2506
日期:1970.8
iodosobenzene in the presence of acetic anhydride. Thermal and Cu-catalyzed decomposition of iodonium ylides can be differentiated and both are explained in terms of diacylcarbene intermediate with different multiplicity. For the sake of comparison diazodimedone and related compounds are also decomposed by Cu-catalysis as well as by photochemicalreaction. Carbene is also found to be a highly probable
碘鎓叶立德的制备方法 Ph–\overset⊕I–\overset\ominusC(COR)(COR') 通过活性亚甲基化合物 H2C(COR)(COR') 与碘苯在醋酸酐。碘鎓叶立德的热和铜催化分解可以区分,两者都可以用具有不同多样性的二酰基卡宾中间体来解释。为了比较,重氮二甲酮和相关化合物也可通过铜催化和光化学反应分解。还发现卡宾是一种很有可能的中间体。在这些研究中,卡宾的自旋多重性是在产物分布的基础上讨论的。值得注意的是,在乙醇中存在均相 Cu 催化剂的情况下,重氮二甲酮会产生 O-H 键的插入产物,2-乙氧基-3-羟基-5,5-二甲基-2-环己烯酮(XVII),而碘鎓叶立德不产生这种化合物。XVII的形成通过假设酮卡宾-Cu-螯合物来解释。
Über die zwei Formen und die Hydrierung des Tetrabenzoyläthylens. (Über die Photochemie des Tetrabenzoyläthylens IX)
作者:H. Schmid、M. Hochweber、H. Von Halban
DOI:10.1002/hlca.19480310704
日期:——
Anhand von Extinktionsmessungen und von Infrarotspektren wird gezeigt, dass die zweiFormen von Tetrabenzoyläthylen Strukturisomere darstellen. Der lichtempfindlichen α-Form kommt die symmetrische Formel I zu, für die lichtstabile β-Form ist die Formel II (a, b, c) die wahrscheinlichste. α- und β-Tetrabenzoyläthylen stellen in theoretischer Beziehung interessante „valenztautomere” Iso-mere dar.
The mechanism of photoisomerization of tetrabenzoylethylene
作者:Mordecai B. Rubin、Wolfram W. Sander
DOI:10.1016/s0040-4039(00)95611-9
日期:——
Photoisomerization of the title compound proceeds via formation of a ketene and rotation about a single bond followed by intramolecular cyclization.
标题化合物的光异构化通过形成烯酮和围绕单键旋转,然后进行分子内环化而进行。
Photosensitized O
<sub>2</sub>
enables intermolecular alkene cyclopropanation by active methylene compounds
作者:Dhruba P. Poudel、Amrit Pokhrel、Raj Kumar Tak、Majji Shankar、Ramesh Giri
DOI:10.1126/science.adg3209
日期:2023.8.4
Cyclopropanes are key features in many preclinical, clinical, and commercial drugs, as well as natural products. The most prolific technique for their synthesis is the metal-catalyzed reaction of an alkene with a diazoalkane, a highly energetic reagent requiring stringent safety precautions. Discovery of alternative innocuous reagents remains an ongoing challenge. Herein, we report a simple photoredox-catalyzed
环丙烷是许多临床前、临床和商业药物以及天然产物的关键特征。最丰富的合成技术是烯烃与重氮烷的金属催化反应,重氮烷是一种高能试剂,需要严格的安全预防措施。发现替代的无害试剂仍然是一个持续的挑战。在此,我们报道了未活化烯烃与活性亚甲基化合物的简单光氧化还原催化分子间环丙烷化反应。反应在中性溶剂中在空气或分子氧(O 2 )与由蓝色发光二极管光激发的光氧化还原催化剂和碘助催化剂(以分子碘形式添加或由烷基碘原位生成)。机理研究表明光敏 O 2在活性亚甲基化合物与烯烃的加成和环闭合过程中碳中心自由基的生成中起着至关重要的作用。
Polyhydroxylated benzene-containing compounds
申请人:——
公开号:US20030139477A1
公开(公告)日:2003-07-24
A method for reducing food intake in a subject and a method for reducing the levels of an endocrine in a subject. The methods include administering to the subject in need thereof an effective amount of a compound of the formula:
1
Also disclosed is a liposomal preparation which includes a liposome and a compound entrapped therein. The entrapped compound is of the formula shown above.