The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources

Abstract

Aryl azides have been used as atom-efficient nitrene transfer reagents in the (porphyrin)ruthenium-catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron-withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubsti-

Copper iodide-catalyzed aziridination of alkenes with sulfonamides and sulfamate esters

“…With an oxidant loading of 2 equiv, an examination of solvent effects showed that reactions carried out in CHCl 3 and CH 2 Cl 2 gave the desired aziridine 3a in near quantitative yields (entries 10 and 11). In contrast, lower product yields of 21-66% were obtained when C 6 H 6 , MeNO 2 1,4-dioxane, and 1,2-dichloroethane were employed as solvents (entries [6][7][8][9].…”

“…[1][2][3][4][5][6][7][8][9][10][11] The ability of aziridines to undergo regio-and stereoselective ring opening reactions also renders this class of compounds as invaluable building blocks in organic synthesis. For this reason, the development of novel synthetic routes for the preparation of aziridines has received significant attention.…”

“…Among the various strategies developed for preparing aziridines, transition metal-catalyzed aziridination of C@C bonds has been reported to be a mild and efficient approach. In recent years, these methods have relied heavily on the use of metal catalysts such as Fe, 5 Mn, 6 Ru, 7 Rh 2 , 8 Ag, 9 Au, 10 and Co 11 with preformed iminoiodinanes (PhI@NSO 2 R, typically R = Ar) or sulfonamide, sulfamate and carbamate esters in combination with a hypervalent iodine(III) oxidant 12 as the nitrogen source. However, a drawback of many of these methodologies has been the need to prepare the metal catalyst, which can be expensive, arduous and time-consuming.…”

Aziridination of alkenes promoted by iron or ruthenium complexes

“…In particular, Ru(porphyrin)CO complexes 36-47 (Chart 1) were very active for the synthesis of N-aryl aziridines obtained from the reaction of alkenes with aryl azides [44].…”

“…The aziridine synthesis was performed by a two-step process where the aniline was first converted into the corresponding aryl azide, by using a modification of a reported method [54], and then the Ru(TPP)CO (36)-catalysed reaction of the azide with the alkene produced the desired aziridine molecule [55,56]. Yields and selectivities of the second step of the flow process were comparable to those achieved by employing the standard batch procedure [44] and the reaction was performed in alkene as the reaction solvent which was easily recycled in the continuous flow process (Scheme 13).…”