通过CuI /(NH 4)2 HPO 4催化O-炔丙基水杨醛与活性亚甲基化合物的反应有效合成2 H -chromen-3-yl衍生物
摘要:
在使用CuI /(NH 4)2 HPO 4催化制备5 H -chromeno [3,4- c ]吡啶的过程中,已经偶然形成了具有不同结构特征的2 H -Chromen-3-基-亚甲基丙二腈/氰基丙烯酸酯/氰基丙烯酰胺。的反应ø -propargyl水杨醛与丙二腈/氰基乙酸乙酯/氰基丙烯酰胺。该方法方便,快速且高产率,并且通过X射线衍射分析最终表征了形成的产物。
Unified Approach to Pyrazole-Fused Heterocyclic and Carbocyclic Motifs through One-Pot Condensation and Intramolecular Dipolar Cycloaddition Reaction
作者:Thachapully Suja、K. Divya、A. Meena
DOI:10.1055/s-0035-1562533
日期:——
Abstract A one-pot synthesis of highly substituted pyrazoles that are fused to dihydrochromenes, dihydroquinolines and cyclopentane motifs, from readily available precursors is reported. The reaction involves conversion of alkyne-tethered aldehydes into the corresponding tosylhydrazones, base-mediated generation of diazo compounds, and subsequent intramolecular dipolar cycloaddition reaction. A range
An efficient synthesis of 2H-chromen-3-yl derivatives via CuI/(NH4)2HPO4 catalyzed reaction of O-propargyl salicylaldehydes with active methylene compounds
alononitriles/cyanoacrylates/cyanoacrylamides with variant structural features have been serendipitously formed during an endeavour to prepare 5H-chromeno[3,4-c]pyridine using CuI/(NH4)2HPO4 catalyzedreaction of O-propargyl salicylaldehyde with malononitrile/ethyl cyanoacetate/cyanoacrylamide. The process is convenient, speedy and high yielding, and the products formed have been finally characterized
在使用CuI /(NH 4)2 HPO 4催化制备5 H -chromeno [3,4- c ]吡啶的过程中,已经偶然形成了具有不同结构特征的2 H -Chromen-3-基-亚甲基丙二腈/氰基丙烯酸酯/氰基丙烯酰胺。的反应ø -propargyl水杨醛与丙二腈/氰基乙酸乙酯/氰基丙烯酰胺。该方法方便,快速且高产率,并且通过X射线衍射分析最终表征了形成的产物。
“On water” cascade synthesis of benzopyranopyrazoles and their macrocycles
Reported herein is an intramolecular 1,3-dipolar cycloaddition strategy for rapid entry into benzopyranopyrazoles (BPP) on water medium as “open flask chemistry” approach. The in situ generation of diazo functionality in two-step sequence from the appropriate alkylated salicylaldehydes undergoes smooth [3 + 2]-cycloaddition with unactivated alkynes/alkenes furnishing benzopyranopyrazoles in good yield
Nitroalkenes derived from O-propargyl salicylaldehyde undergo facile Michael addition with indoles leading to indole-derived Michael adducts. Intramolecular nitrileoxide cycloaddition (INOC) of the Michael adducts results in isoxazolobenzoxepanes in good to excellent yields.
A syn-arylative nickelation followed by nucleophilic syn-selective cyclization of o-propargyloxy benzaldehydes is achieved toward the synthesis of chromanol skeletons with alkenyl substitution at C3. The capture of the intermediate vinyl nickel in its cis geometry is done also with a Michael acceptor to synthesize 4-alkylated derivatives. This protocol is equally applicable to o-propargylamino benzaldehydes to access 3,4-disubstituted tetrahydro-hydroquinolines.