Toward accessible 3H-pyrroles

Abstract

Yet recently difficult-to-access 3H-pyrroles, rare nonaromatic pyrrole systems, now have become readily available due to essential modification of their synthesis from aryl isoalkyl ketoximes and acetylene in the KOH/DMSO system allowing to carry out the process under atmospheric pressure. In contrast to the known procedure implemented under pressure, the modified method is expedient, much safer and feasible that makes it friendly for any laboratory.

Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

“…Although acetylene is one of the most important building blocks in industrial chemistry, its application in laboratory practice is severely limited by the high fire hazard and substantial risk of explosion. The use of compressed acetylene requires special facilities and techniques as well as strict safety precautions . To overcome these restrictions, calcium carbide was suggested as a convenient and rather safe source of acetylene, , and we decided to explore this CaC 2 -based method in our experiments.…”

“…The use of compressed acetylene requires special facilities and techniques as well as strict safety precautions. 63 To overcome these restrictions, calcium carbide was suggested as a convenient and rather safe source of acetylene, 64,65 and we decided to explore this CaC 2based method in our experiments.…”

Diastereoselective synthesis of tetrahydropyrrolo[1,2-d]oxadiazoles from functionalized Δ1-pyrrolines andin situgenerated nitrile oxides

“…This task happens to be in line with our current interest in the chemistry of Δ 1 -pyrrolines. We earlier developed simple synthetic routes to 5-hydroxypyrrolines and 3 H -pyrroles based on the reaction of ketoximes with only one C–H bond adjacent to the oxime function with calcium carbide 14 or acetylene gas 15 in the presence of cheap and easy-to-handle MOH (M = Na, K)/DMSO superbase catalytic systems (Scheme 2). These unique aza-heterocycles turned out to be fruitful reactive intermediates in diverse synthetic transformations.…”