辐射后,结晶的4-甲氧基苯基-1,4-二氢吡啶3经历几乎定量的[2 + 2]环加成反应,通过开环中间体2形成中心对称的多官能化3,9-二氮杂四环烷3。1 H NMR光谱数据以及X射线晶体结构分析证实了3的中心对称性。事实证明,二聚化反应是由可能发生反应的双键之间的最近距离以及由构象确定的堆积约束进行拓扑化学控制的。通过单体1的一种二聚化和一种光稳定的衍生物的X射线晶体结构分析显示了后者的因素。
One-Pot Synthesis of N-Substituted 4-Aryl-1,4-dihydropyridines Under Solvent-Free Conditions and Microwave Irradiation
作者:Saeed Balalaie、Elahe Kowsari
DOI:10.1007/s007060170012
日期:2001.12
The three-component condensation of benzaldehyde derivatives, alkyl propiolates, and primary amines catalyzed by silicagel, zeolite HY, montmorillonite K-10, and acidic alumina undermicrowaveirradiation gave N-substituted 4-aryl-1,4-dihydropyridines in short reaction times and high yields. The best results were obtained with silicagel.
Solid-state Synthesis of Novel 3,9-Diazatetraasteranes
作者:Andreas Hilgeroth
DOI:10.1246/cl.1997.1269
日期:1997.12
A novelsolid-statesynthesis of 3,9-diazatetraasteranes is reported, giving polyfunctionalized derivates in a single-step reaction with nearly quantitative yields by photochemically induced [2+2]cycloaddition reactions.
of 3 was confirmed by 1H NMR spectral data as well as by X-ray crystal structure analysis. The dimerization reactions prove to be topochemically controlled by the nearest distance between potentially reacting double bonds, as well as by the conformationally determined packing restraints. This latter factor is shown by the X-ray crystal structure analysis of one dimerizing and one photostable derivative
辐射后,结晶的4-甲氧基苯基-1,4-二氢吡啶3经历几乎定量的[2 + 2]环加成反应,通过开环中间体2形成中心对称的多官能化3,9-二氮杂四环烷3。1 H NMR光谱数据以及X射线晶体结构分析证实了3的中心对称性。事实证明,二聚化反应是由可能发生反应的双键之间的最近距离以及由构象确定的堆积约束进行拓扑化学控制的。通过单体1的一种二聚化和一种光稳定的衍生物的X射线晶体结构分析显示了后者的因素。
Novel solid-state synthesis of dimeric 4-aryl-1,4-dihydropyridines
作者:Andreas Hilgeroth、Frank W. Heinemann
DOI:10.1002/jhet.5570350217
日期:1998.3
On irradiation in the solid state the 4-aryl-1,4-dihydroypridines 1 undergo [2+2] cycloadditon to centrosymmetric head-to-tail dimers 3 and 4a. The almost exclusive formation of the cage dimers 3 via the C2-symmetric syn-dimers 2 takes place in nearly quantitative yields, in contrast with the cycloaddition reaction of the anti-dimer 4a, which is accompanied by photooxidation to pyridine 5a.