Core-Modified, <i>meso</i>-Alkylidenyl Porphyrins and Their Expanded Analogues: A New Family of Nonplanar Porphyrinoids
作者:Seung-Doo Jeong、Seong-Jin Hong、Kee Jong Park、Sihyun Ham、Jonathan L. Sessler、Vincent Lynch、Chang-Hee Lee
DOI:10.1021/jo070872k
日期:2007.8.1
(20) revealed that all four pyrrole rings displayed an inverted geometry, presumably reflecting the strong hydrogen-bonding extant between the pyrrole N−H proton and the carbonyl group of the malonate moiety in the solid state. On the other hand, the expanded oxabenziporphyrin (14) was found to possess a severely distorted geometry with only one pyrrole ring being inverted. Careful analysis of the structure
Sulfuric acid-modified PEG-6000 (PEG–OSO3H): a biodegradable, reusable solid acid catalyst for highly efficient and eco-friendly synthesis of novel bis-Knoevenagel products under solvent-free conditions
作者:Zeba N. Siddiqui、Tabassum Khan
DOI:10.1016/j.tetlet.2013.05.012
日期:2013.7
PEG-6000 (PEG–OSO3H) is used as a highlyefficient, biodegradable, and reusable acid catalyst for the synthesis of novel acyclic and heterocyclic bis-Knoevenagel products under thermal solvent-free conditions. The remarkable features of this green, new methodology are high conversions, cleaner reaction profile, simple experimental and work-up procedure, and economic viability. The catalyst is characterized