Conversion of Esters to Amides with Dimethylaluminum Amides: N,N ‐Dimethylcyclohexanecarboxamide

Abstract

Conversion of esters to amides with dimethylaluminum amides: N,N ‐dimethylcyclohexanecarboxamide reactant: 7.10 g. (0.0500 mole) of methyl cyclohexanecarboxylate product: N,N ‐dimethylcyclohexanecarboxamide

Terminating catalytic asymmetric Heck cyclizations by stereoselective intramolecular capture of η3-allylpalladium intermediates: total synthesis of (−)-spirotryprostatin B and three stereoisomers

“…24,25 Trimethylaluminum-mediated conversion of ester 21 to anilide 22 proceeded smoothly in 80% yield 26. Protection of the resulting amide nitrogen with SEM-Cl afforded ( E )-2,4-hexadienamide substrate 23 in good overall yield.…”

Total synthesis of (−)-ephedradine A: an efficient construction of optically active dihydrobenzofuran-ring via C–H insertion reaction

“…Upon treatment of 18 and the alcohol 19 5 with DEAD and PPh 3 , the condensation reaction proceeded smoothly to give 20 (Scheme 6). Removal of the Ns group of 20 and subsequent treatment of the secondary amine 21 with dimethylaluminum chloride 18,19 in refluxing CH 2 Cl 2 gave the amide 23 in 67% yield. The amide formation would be promoted by the dual activation of the aluminum which coordinate both of the ester-group and the secondary amine in 22.…”

“…After stirring for 30 min at the same temperature, the reaction mixture was concentrated under reduced pressure. The residue was purified by flash chromatography (50% AcOEt in n-hexane) to afford 17 (5.10 g, 9.27 (18). To a solution of 17 (5.10 g, 9.27 mmol) in THF (40 ml) and MeOH (40 ml) was added Ba(OH) 2 $8H 2 O (3.21 g, 10.2 mmol, 1.1 equiv.)…”

Fluorescent probes of the isoxazole–dihydropyridine scaffold: MDR-1 binding and homology model

“…We have found that modest yields can be obtained for 2 using our double activation method, 17 which uses a lanthanide catalyst in the presence of a Weinreb activated amine. 18 The resulting tethered amines can be transformed to fluorophore-labeled analogs quite effectively. Thus, a series of probes with differing tether lengths ( 3a–d ), and diverse fluorophores ( 3–7 ) were readily available.…”