Synthesis of Functionalized Pyrrolizidines/Pyrrolidines Incorporating a Spirooxindole Motif through [3+2] Cycloaddition
摘要:
Dimethyl 2-(aryloxy)fumarates and dimethyl 2-(alkyl- or arylthio)fumarates are shown to be efficient dipolarophiles in 1,3-dipolar cycloaddition reaction with azomethine ylides, which are generated by the reaction of isatin with the secondary amino acids proline or sarcosine. In these reactions, dimethyl 2-(alkyl- or arylthio)fumarates afforded spirooxindolopyrrolizidines or -pyrrolidines in high yields with excellent regioselectivities, while dimethyl 2-(aryloxy)fumarates produced mixtures of regioisomers. DFT calculations at the B3LYP/6-31G(d,p) level were consistent with the observed results. Tri- and tetracyclic compounds were obtained through regio- and stereoselective intramolecular cycloaddition of O-vinylic salicylaldehyde with secondary amino acids.
Trimethylamine catalyzed stereoselective reaction between dimethyl acetylenedicarboxylate and phenols
作者:Farough Nasiri、Bahareh Atashkar
DOI:10.1007/s00706-008-0919-z
日期:2008.10
Stereoselective reaction of various substituted phenols with dimethylacetylenedicarboxylate in the presence of a catalytic amount of aqueous trimethylamine solution in dichloromethane leads to dimethyl 2-phenoxymaleates in good to excellent yields under mild condition.
An efficient and green approach for the synthesis of vinyl aryl ethers in the presence of guanidine hydrochloride
作者:SEYED MOHAMMAD VAHDAT、ROBABEH BAHARFAR
DOI:10.3906/kim-1002-24
日期:——
A stereoselective procedure for vinyl aryl ether bond formation by direct coupling of dialkyl acetylenedicarboxylates and substituted phenols or naphthols under mild reaction conditions has been developed. Using guanidine hydrochloride as a new catalyst and water-acetone as green solvent, dialkyl acetylenedicarboxylates were reacted with substituted phenols or naphthols in room temperature to produce vinyl aryl ethers in good to excellent yields.
Diastereoselective O-Vinylation of Phenols using DMAD under Mild Reaction Conditions
作者:Ebrahim Kianmehr、Katayoun Tabatabai、Alireza Abbasi、Hamideh Shokouhi Mehr
DOI:10.1080/00397910802219163
日期:2008.7.24
An efficient and straightforward pyridine-catalyzed method allowing selective O-vinylation of phenols with DMAD is reported. The reaction is diastereoselective and leads exclusively to (Z)-configuration in high yields.
A green and rapid approach for the stereoselective vinylation of phenol, thiol and amine derivatives in water
The stereoselective formation of C–O, C–S and C–N bonds by the reaction of phenols, thiols and amines with activated alkynes is described. The reactions are successfully conducted in water with excellent yields at room temperature. The lack of organic solvent use in the work-up procedure, the short reaction time and the environmentally benign mild reaction conditions are advantages of this method.
Dimethyl 2-(aryloxy)fumarates and dimethyl 2-(alkyl- or arylthio)fumarates are shown to be efficient dipolarophiles in 1,3-dipolar cycloaddition reaction with azomethine ylides, which are generated by the reaction of isatin with the secondary amino acids proline or sarcosine. In these reactions, dimethyl 2-(alkyl- or arylthio)fumarates afforded spirooxindolopyrrolizidines or -pyrrolidines in high yields with excellent regioselectivities, while dimethyl 2-(aryloxy)fumarates produced mixtures of regioisomers. DFT calculations at the B3LYP/6-31G(d,p) level were consistent with the observed results. Tri- and tetracyclic compounds were obtained through regio- and stereoselective intramolecular cycloaddition of O-vinylic salicylaldehyde with secondary amino acids.