Synthesis and antagonist activities of 4-aryl-substituted conformationally restricted cyclopentenyl and cyclopentanyl-glutamate analogues

Enantioselective synthesis of (−)-paeonilide

“…[85][86] According to literature precedents, this method was successfully applied on ,-unsaturated esters and tolerates several functional groups, e.g. esters, epoxides and ethers.…”

Synthesis and inhibitory activities at mGluRs of 3-alkylated and N-alkylated cyclopentyl-glutamate analogues

“…Reduction of ,-unsaturated esters and other electron deficient alkenes using magnesium metal in dry methanol has been described by us and others to be a selective and efficient method to provide the desired cis 18 as the major product. 8,[12][13][14] The cis orientation of the two carboxylic groups in 18 is considered to be significant structural features for activities. 6 The selectivity observed in the magnesium-methanol reduction of compound 16 might be due to the formation of the Mg(II) complex B, as shown in Figure 8, which upon stereoselective protonation would give compound 18 as the major product.…”

“…The racemic N-alkylated compounds 22a-e were obtained according to Scheme 5, the imine intermediates 21a-e were obtained by treating the known 15 8 with various aldehydes in dry THF in the presence of powdered molecular sieves, then followed by the reduction in the presence of NaBH 3 CN and acetic acid, in methanol to afford 21a-e in acceptable yields. Acid hydrolysis of 21a-e provided the hydrochloride salts of compounds 22a-e in high yields (Table 4).…”

“…8 In order to further understand the SAR of the derivatives of rac-3, we aimed to synthesise its 3-alkylated and N-alkylated derivatives and investigate their biological activities.…”

Regio- and Stereoselective Synthesis of Functionalized Cyclopentene Derivatives via Mizoroki–Heck Reactions

“…Please note that structurally related substrate 2j has been reported to react with aryl iodides under Jeffery conditions with predominantly si face attack. 14 The observed selectivity was explained by coordination of the arylpalladium complex to the carbamate moiety. 15,16 Using DFT calculations we have shown that, as for 2a, the monoprotected amine is facing the metal in the migratory insertion (energy difference: −4.7 kcal mol −1 ).…”