Highly Selective Intra- and Intermolecular Coupling Reactions of Diazo Compounds to Form cis-Alkenes Using a Ruthenium Porphyrin Catalyst
摘要:
[Ru(2,6-Cl2TPP)(CO)] catalyzed intramolecular coupling reactions of bisdiazoacetates and intermolecular coupling reactions of monodiazoacetates to afford the coupling products in up to 76% and 93% yields, respectively. Only the cis isomers were obtained from the reactions. Employing such a ruthenium-catalyzed coupling reaction of a diazo compound as a key step allowed the synthesis of Patulolide B in 67% yield with a ratio of >40:1 against its trans isomer.
Assembly of ion channel mimics from a modular construction set
作者:Thomas M. Fyles、Tony D. James、Allana Pryhitka、Mohammad Zojaji
DOI:10.1021/jo00078a026
日期:1993.12
Ion channel mimics were assembled from a modular construction set consisting of core units, derived from polycarboxylate 18-crown-6 ethers, wall units, derived from macrocyclic tetraesters, and polar head groups which provide overall amphiphilic character. The preparation of symmetrical and side-discriminated macrocyclic tetraesters from diols and maleic anhydride gave the required macrocycles in low yields by acid-catalyzed esterification, or by carboxylate alkylation. Addition of 1 equiv of 3-mercaptopropanol to the macrocyclic dienes gave the wall unit precursor. Coupling of the walls to the crown ether via esters was achieved by carboxylate alkylation. The syntheses were completed by Michael addition of head group thiolates. Twenty-one candidate ion channels of molecular weight 1600-4800 g/mol were prepared and characterized.