A General Access to Propargylic Ethers through Brønsted Acid Catalyzed Alkynylation of Acetals and Ketals with Trifluoroborates
作者:Matthew Baxter、Yuri Bolshan
DOI:10.1002/chem.201502797
日期:2015.9.21
A general Brønsted acid catalyzed methodology for the alkynylation of acetals and ketals with alkynyltrifluoroborate salts has been developed. The reaction proceeds rapidly to afford valuable synthetic building block propargylic ethers in good to excellent yields. Unlike Lewis acid catalyzed transformations of trifluoroborates, this approach does not proceed via unstable organodifluoroborane intermediate
syntheses. However, the synthesis of acid–base catalysts is problematic due to the neutralization of acidic and basic groups. This work reports a facial approach to solve this problem via the synthesis of a novel bifunctional polymer using inexpensive materials and easy methods. In this way, at the first step, heterogeneous poly (styrene sulfonic acid‐n‐vinylimidazole) containing pentaerythritol tetr
Hierarchically Pore Structure poly 2-(Dimethyl amino) ethyl methacrylate/Hi-ZSM-5: A Novel Acid–Base Bi-functional Catalyst as Heterogeneous Platform for a Tandem Reaction
作者:Roozbeh Javad Kalbasi、Anahita Khojastegi
DOI:10.1007/s10562-018-2301-z
日期:2018.3
A simple method is developed to prepare an efficient and low cost acid–base bifunctional catalyst by using poly 2-(dimethyl amino) ethyl methacrylate as a basic part and hierarchical ZSM-5 as an acidic part of the catalyst. Tandemreaction of deacetalization–Knoevenagel condensation was selected to evaluate the prepared catalyst and the outcomes were excellent.Graphical Abstract
Facile Synthesis of Unsubstituted β,β′-Linked Diformyldipyrromethanes
作者:Zhan Zhang、Ji-Young Shin、David Dolphin
DOI:10.1021/jo802114h
日期:2008.12.5
Unsubstituted beta,beta'-linked diformyldipyrromethanes are promising precursors for the synthesis of novel poly dipyrromethene ligands and N-confused porphyrins. A strategy has been developed to selectively synthesize unsubstituted beta,beta'-linked diformyldipyrromethanes in moderate yields starting from 2-formylpyrrole.