Highly Regioselective Synthesis of Substituted Pyrroles Utilizing Low-Valent Titanium Reagent
作者:Daqing Shi、Guolan Dou、Chunling Shi、Zhengyi Li、Shun-Jun Ji
DOI:10.1055/s-2007-990787
日期:2007.10
A short and efficientsynthesis of substituted pyrroles was accomplished in good yields via the novel coupling cyclization reaction of 1,3-diketones with imines promoted by low-valenttitaniumreagent. High regioselectivity was achieved and the structures of two of the products were confirmed by X-ray diffraction studies.
通过低价钛试剂促进的 1,3-二酮与亚胺的新型偶联环化反应,以良好的收率完成了取代吡咯的短而有效的合成。实现了高区域选择性,并且通过 X 射线衍射研究证实了两种产物的结构。
β-Lactam derivatives as enzyme inhibitors: halogenated β-lactams and related compounds
作者:Ali Elriati、Jutta Loose、Roswitha Mayrhofer、Hans-Joachim Bergmann、Hans-Hartwig Otto
DOI:10.1007/s00706-007-0837-5
日期:2008.7
at position 4, or at both positions. The influence of the halogen atoms on the reactivity of the β-lactam ring, visible by the carbonyl frequence in their IR spectra, was studied. A selection of compounds was tested as inhibitors of the serin protease porcine pancreatic elastase. No simple correlation between IR frequence and biological activity was found. Finally, the base induced rearrangement of
Substituent Cross-Interaction Effects on the Electronic Character of the CN Bridging Group in Substituted Benzylidene Anilines − Models for Molecular Cores of Mesogenic Compounds. A <sup>13</sup>C NMR Study and Comparison with Theoretical Results
作者:Helmi Neuvonen、Kari Neuvonen、Ferenc Fülöp
DOI:10.1021/jo0600508
日期:2006.4.1
could be verified. The electroniceffects of the neighboring aromatic ring substituents systematically modify the sensitivity of the CN group to the electroniceffects of the benzylidene or aniline ring substituents. Electron-withdrawing substituents on the aniline ring decrease the sensitivity of δC(CN) to the substitution on the benzylidine ring, while electron-donating substituents have the opposite
在CDCl 3中,对一系列介晶分子模型化合物(即C 13)测量了13 C NMR化学位移δC (C N)。取代的亚苄基苯胺p -X C 6 H 4 CH NC 6 H 4 p -Y(X = NO 2,CN,CF 3,F,Cl,H,Me,MeO或NMe 2; Y = NO 2,CN ,F,Cl,H,Me,MeO或NMe 2)。δ的取代基依赖性Ç(CN)被用作研究电子取代基对偶氮甲碱单元的作用的工具。亚苄基取代基X有δ的反向效应Ç(C N):吸电子原因屏蔽的取代基,而给电子性的人的行为相反,感应效果清楚地在共振效应为主。相反,苯胺取代基Y发挥正常作用:吸电子取代基引起屏蔽,而供电子取代基引起C N碳屏蔽,感应效应和共振效应的强度非常相似。此外,可以验证X和Y之间是否存在特定的交叉相互作用。相邻芳环取代基的电子效应可系统地改变C的灵敏度N基团对亚苄基或苯胺环取代基的电子作用。吸电子苯胺环上的取代基降低δ的灵敏度Ç(C
Triggering Lewis Acidic Nature through the Variation of Coordination Environment of Cd-Centers in 2D-Coordination Polymers
作者:Nikhil Kumar、Avijit Kumar Paul
DOI:10.1021/acs.inorgchem.9b02997
日期:2020.1.21
frameworks relies on careful selection of metals and versatile organic ligands. A newly designed pyrazole-based dicarboxylate ligand, 5-(3,5-dimethyl-1H-pyrazol-1-yl) 1,3-benzenedicarboxylic acid (H2L), was utilized to obtain two new Cd-based coordinationpolymers I [Cd(L)(H2O)]·H2O and II [Cd(L)] under similar reaction conditions via solvothermal strategy. Single-crystal X-ray data confirmed that compound I