Access to Sultams by Rhodium(III)‐Catalyzed Directed CH Activation

Abstract

Director's cut: The pharmaceutically relevant sulfonamide group is shown to be a competent directing group for [Cp*Rh(OAc)(2)]-catalyzed C-H functionalizations. Reactions of the cyclometalated intermediate with internal alkynes provide access to a wide range of sultam derivatives. The reaction is high yielding and works best under aerobic conditions with catalytic amounts of CuOAc as an oxidation mediator. Cp* = C(5)Me(5).

Iridium (III) and rhodium (III) triazoles by 1,3-dipolar cycloadditons to a coordinated azide in iridium (III) and rhodium (III) compounds

“…We further studied the direct reaction of 5 and 10 with NaN 3 by using low stoichiometric amounts of NaN 3 and performing the reaction for only 1 h which resulted in the formation of the terminal azido complexes 15 and 20. Thus, we were able to prepare the terminal azido complexes [(η 5 [35] ((η 6 -arene = p-cymene) by X-ray analysis. Hence, in this study, no attempts have been made for single-crystal analysis of these azido complexes.…”

“…Half-sandwich iridium (III) and rhodium (III) complexes have received attention in the past few decades owing to their catalytic activities [1][2][3][4][5][6] and biological properties [7,8]. Optically active half-sandwich metallocene complexes of rhodium (III) and iridium (III) have shown ability to act as active stereospecific catalysts [9].…”

“…Other Cp*M compounds, such as the cationic iridium complex, [(η 5 -C 5 Me 5 )IrMe(PMe 3 )(ClCH 2 Cl)] + [BAr 4 ] − (Ar = aryl), exhibit interesting reactivity in C-H activation reactions of various functionalized substrates at ambient temperature [10]. The Cp*M complexes were extensively explored in various catalytic reactions namely, hydrogenation [3], asymmetric catalysis [4], and more recently in the reactions involving C-H activation [5,6]. In biology, both the Cp* iridium (III) and rhodium (III) complexes bearing polypyridyl ligands have shown DNA intercalating properties [11][12][13], while iridium (III) [7] and rhodium (III) [8] complexes with N,N chelate ligands have exhibited anticancer properties.…”

“…The formation of these complexes was readily followed from their infrared spectra. The infrared spectra showed disappearance of starting compounds azide peaks at 2046 and 2057 cm −1 for rhodium and iridium azide complexes [{(η5 -C 5 Me 5 )M(μN 3 )Cl} 2 ] (M = Rh or Ir), and new peaks appeared at 2019 and 2034 cm −1 corresponding to the terminal azide stretching frequencies…”

Rhodium(III)‐Catalyzed Amidation of Unactivated C(sp3)H Bonds

“…[2] In the past decade,o nly limited examples of direct amination of C(sp 3 )ÀHBonds has been reported by using palladium, [3,4] rhodium(II), [5] copper, [6] iridium, [7] and other catalysts. [10,11] Thus, there are only af ew examples on the functionalization of unactivated C(sp 3 ) À Hb onds using rhodium(III) catalysis,a s in the coupling with alkynes, [12] activated forms of arenes, [13] and azides [14] (Scheme 1a). [10,11] Thus, there are only af ew examples on the functionalization of unactivated C(sp 3 ) À Hb onds using rhodium(III) catalysis,a s in the coupling with alkynes, [12] activated forms of arenes, [13] and azides [14] (Scheme 1a).…”