Various aromatic and heterocyclic oxazolines were directly converted to respective cyanomethyl esters with pyridinium hydrobromide perbromide in water at room temperature.
Titanium-Mediated Addition of Grignard Reagents to Acyl Cyanohydrins: Aminocyclopropane versus 1,4-Diketone Formation
作者:Paul Setzer、Gwénaël Forcher、Fabien Boeda、Morwenna S. M. Pearson-Long、Philippe Bertus
DOI:10.1002/ejoc.201301251
日期:2014.1
The 1,2-dianion reactivity of the reagent generated from EtMgBr and titanium isopropoxide was illustrated when N-acyl cyanohydrins were used as substrates (>20 examples), giving both aminocyclopropane derivatives and 1,4-dicarbonyl compounds. When the reaction was performed in diethyl ether, 5-hydroxy-1,4-diketones were the main product. Under specific conditions (use of tetrahydrofuran and a bulky
The first oxidativecoupling of alkylnitriles with aromatic carboxylicacids using di-tert-butyl peroxide (DTBP) as oxidant was achieved under the catalysis of ionic Fe(III) complexes bearing an imidazolinium cation. This protocol features nontoxic iron catalysis, direct α-C(sp3)–H bond oxidative esterification of alkylnitriles, non-prefunctionalized starting materials, and a broad substrate scope
Pyridyl-1,3,4-thiadiazole; eine neue Variante der Thiadiazol-Synthese
作者:P. Hemmerich、B. Prijs、H. Erlenmeyer
DOI:10.1002/hlca.19580410714
日期:——
Thiosemicarbazones of aromatic aldehydes react with acetic anhydride to give well-defined N4,S-diacetyl derivatives, which readily undergo oxidativecyclisation to 2-aryl-4-acetamido-1,3,4-thiadiazoles. From these intermediates, aryl-thiadiazoles – especially 2-(2′-pyridyl)-1,3,4-thiadiazole, inaccessible by the common methods – can be obtained by acidic deacetylation, SANDMEYER substitution and catalytic