A Simple Method for the Synthesis of Substituted Benzylic Ketones: Homologation of Aldehydes via the in Situ Generation of Aryldiazomethanes from Aromatic Aldehydes
作者:Steven R. Angle、Martin L. Neitzel
DOI:10.1021/jo000446y
日期:2000.10.1
A general method for the homologation of aldehydes to benzylic ketones has been developed. Aryldiazomethanes were generated in situ in the presence of an aldehyde by simply heating the tosylhydrazones of aromatic aldehydes in the presence of a stoichiometric amount of base in polar protic solvents. The resulting polar protic solvent promoted homologation afforded benzylic ketones in moderate to excellent
Low-valent titanium induced reductive coupling reaction of carboxylic derivatives with aromatic ketones
作者:Da-qing Shi、Jian-xie Chen、Wen-ying Chai、Wei-xing Chen、Tsi-yu Kao
DOI:10.1016/s0040-4039(00)60493-8
日期:1993.4
The intermolecular and intramolecular coupling reaction of carboxylic derivaties with aromatic ketones induced by titaniumtetrachloride and zinc powder was studied.
研究了四氯化钛和锌粉诱导的羧酸衍生物与芳族酮的分子间和分子内偶联反应。
Supramolecular Steric Effects as the Means of Making Reactive Carbon Radicals Persistent. Quantitative Characterization of the External Surface of MFI Zeolites through a Persistent Radical Probe and a Langmuir Adsorption Isotherm
作者:Takashi Hirano、Wei Li、Lloyd Abrams、Paul J. Krusic、M. Francesca Ottaviani、Nicholas J. Turro
DOI:10.1021/jo991298i
日期:2000.3.1
photochemistry of tetraphenylacetone (1) adsorbed on the external surface of a MFI zeolite (the sodium form of LZ-105) has been investigated in combination with computational chemistry, surface area measurements, EPR analysis, and classical adsorption isotherms. All of the methods are consistent with a supramolecular structural model in which 1 is first adsorbed strongly through intercalation of a single
结合计算化学,表面积测量,EPR分析和经典吸附等温线,研究了吸附在MFI沸石(钠形式的LZ-105)外表面上的四苯丙酮(1)的光化学。所有方法均与超分子结构模型一致,在超分子结构模型中,首先通过将单个苯环插入LZ-105外表面(位点I)上的孔中,从而将1强吸附,然后再与LZ-105外部构架之间的结合较弱。孔(位置II),直到形成1的单层。从计算和表面积测量两者,估计外表面上的位置I孔将被填充至约1。1 / LZ-105的0.3-0.5 wt%/ wt加载量,相当于6.5 x 10(18)(ca. 每克沸石有10(-)(5)mol的孔或1的分子吸附在孔中。ca的超分子组成。LZ-105上1的0.3-0.5%表征了光化学和EPR测量的“断裂点”,因为它表示I位置的1饱和孔的饱和度值。这些结论在吸附的实验等温线中得到定量支持。 1在LZ-105上 插入位置I孔中的1的光解会导致分裂为两个同分异构
Regioselective Allylation of Ketenes Promoted by SmI<sub>2</sub>
作者:Norikazu Miyoshi、Seiji Takeuchi、Yoshiaki Ohgo
DOI:10.1246/bcsj.67.445
日期:1994.2
Ketenes react with various allylic halides mediated by 2 equiv samarium(II) diiodide (SmI2) to the ketenes to afford allylated ketones in good yields. In the reaction with γ-substituted allylic halides, the regioselectivity is influenced by the olefinic geometry of allylic halides. By using γ-substituted (E)-allylic halides, the allylation proceeds on the less hindered site (α-position) of allylic groups predominantly and the tendency was enhanced by the addition of HMPA.