Dirhodium(ii)-catalyzed diamination reaction via a free radical pathway

Abstract

Unlike C-N bond formation with classical dirhodium(II)-nitrenoids as the key intermediate, dirhodium(II)-catalyzed 1,2-and 1,3-diamination reactions are realized by a free radical mechanism. A mechanistic study revealed that the reactions undergo...

Rhodium(II)‐Catalyzed C(sp3)−H Diamination of Arylcyclobutanes

“…Based on the above results and previous literature, [17c,18] a possible reaction mechanism is proposed (Scheme 4). The catalytic cycle starts with the NFSI oxidation of the rhodium catalyst forming ⋅NSI and Rh 2 (II, III) species, followed by ⋅NSI seizing the benzyl hydrogen of the cyclobutane substrate to produce benzyl radical A .…”

Energy Transfer-Enabled Unsymmetrical Diamination Using Unprecedented Bifunctional Nitrogen-Radical Precursors

“…Especially sensitive functional groups, such as chloro, bromo, acyloxy, ester, amide, cyano, formyl, and even boronic ester, were well-tolerated under the optimized conditions. To further test the compatibility of this method in more structurally complex contexts, several complicated indole-containing biologically active compounds such as Boc-protected Z-Trp-OMe and indoles embedded in gemfibrozil or dehydrocholic acid, were tested, affording the corresponding diamines in moderate yields (41)(42)(43). Unprotected indoles and N-alkyl or N-aryl indoles were, however, not suitable for this protocol.…”

“…From the synthetic perspective, unsymmetrical diamination is a more attractive but challenging task, 29 due to the lack of suitable amination reagents, and potential regio-and diastereoselectivity issues. Although some elegant unsymmetrical alkene diaminations have been realized, [30][31][32][33][34][35][36][37][38][39][40][41] methods to access a diamine precursor which could be easily and orthogonally converted into synthetically relevant unsymmetrical diamine products are still highly desirable.…”

“…First, the majority of these methods require transition-metals or hyper-valent iodine reagents as catalysts. [9][10][11][12][13][14][15][16][17][18][19][23][24][25]28,[33][34][35][36][37][38][39][40][41] In addition, the utilization of stoichiometric amounts of metal reagents (e.g. osmium or cobalt), [7][8] chemical oxidants, 11,15,22,23,27,28,33,34,37,38 or azide reagents, [14][15][16][18][19][20]26,28,40,41 leads to the issues on cost, environment, and safety.…”

Recent Advances in Mono‐ and Difunctionalization of Unactivated Olefins

“…Later in 2021, Yuanhua Wang et al disclosed dirhodium(II)catalyzed diamination of alkenes via a free radical mechanism to afford a series of corresponding products 119 (Scheme 44). [43] Among all the screened catalysts Rh 2 (esp) 2 and solvent DCE was found to be effective for this transformation. Optimization condition was realized with Rh 2 (esp) 2 as catalyst, N-fluorobenzenesulfonimide (NFSI) and trimethylsilyl azide (TMSN 3 ) as nitrogen source and K 2 CO 3 as base in DCE at room temperature under argon.…”