Dirhodium(II)‐Catalyzed Intramolecular CH Amination of Aryl Azides

Shen, Mei‐Hua; Leslie, Brooke E.; Driver, Tom G.

doi:10.1002/ange.200800689

Cited by 93 publications

(22 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[7][8][9][10][11] To further validate the utility of C À H amination methodology based on a cobalt(II) catalyst and azides, we envisioned a general strategy for the synthesis of 1,3-diamines from monoamines through the key step of the intramolecular C À H amination of sulfamoyl azides with [Co(Por)] (Scheme 1). We report herein a cobalt(II)-based catalytic system that is highly effective for the intramolecular 1,6-CÀH amination of sulfamoyl azides to furnish six-membered cyclic sulfamides.…”

mentioning

confidence: 99%

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

et al. 2010

View full text Add to dashboard Cite

Amino groups exist ubiquitously in natural products and synthetic molecules, and play key roles in a wide range of important applications. Consequently, immense effort has been devoted to the development of efficient and selective processes for the preparation of amines.[1] Among different approaches, the catalytic amination of abundant C À H bonds on the basis of a metal-mediated nitrene-insertion pathway is one of the most general and direct methods for installing nitrogen functionalities.[2] The promise of this approach as a synthetically useful methodology has been demonstrated with a number of intramolecular C À H amination processes through the combined use of Rh II 2 -based catalysts and iminoiodane nitrene sources. [2,3] Notably, Du Bois and coworkers elegantly demonstrated that N-Boc-protected sulfamides could be selectively converted into cyclic sulfamides by [Rh 2 (esp) 2 ] in combination with PhI(OAc) 2 and MgO to provide access to synthetically useful 1,3-diamines (esp = a,a,a',a'-tetramethyl-1,3-benzenedipropionate).[4] The Rh II 2 -based intramolecular amination was shown to be effective for both secondary and tertiary CÀH bonds with stereospecificity and high diastereoselectivity. However, the amination of strong primary CÀH bonds had yet to be demonstrated. [5] Moreover, the catalytic system was unsuitable for simple Nalkyl sulfamides, which were oxidatively degraded by the stoichiometric oxidant, PhI(OAc) 2 . [4] As stable metalloradicals, cobalt(II) complexes of porphyrins, [Co(Por)], have emerged as a new class of catalysts for CÀH amination.[6] The cobalt(II)-based metalloradical amination (MRAm) is different from the commonly studied Rh 2 system, as it can operate effectively with various azide substrates without the need for terminal oxidants and other additives. [7][8][9][10][11] To further validate the utility of C À H amination methodology based on a cobalt(II) catalyst and azides, we envisioned a general strategy for the synthesis of 1,3-diamines from monoamines through the key step of the intramolecular C À H amination of sulfamoyl azides with [Co(Por)] (Scheme 1). We report herein a cobalt(II)-based catalytic system that is highly effective for the intramolecular 1,6-CÀH amination of sulfamoyl azides to furnish six-membered cyclic sulfamides. Not only excellent regioselectivity, but also high diastereoselectivity and stereospecificity were observed with the catalytic system. The cobalt(II)-catalyzed amination is operationally simple, as it proceeds under neutral and nonoxidative conditions without the need for other reagents, and N 2 is the only byproduct. Consequently, the degree of functional-group tolerance is high, and the reaction can be applied to substrates with various substituents, such as oxidizable amide and sulfide groups. An important feature of this catalytic system is the effective amination of strong primary C À H bonds, as well as secondary and tertiary C À H bonds.A wide range of sulfamoyl azides 2 were conveniently prepared from the corresponding amines 1 on the bas...

show abstract

mentioning

confidence: 99%

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The Driver group has extensively explored the synthetic utility of this shift in their studies of Rh-catalyzed decomposition of stryryl azides, presumably through similar benzylic carbocations. [24] To test this hypothesis, gem-diphenyl-substituted stryryl aniline 13a was prepared and subjected to the optimized visible light photocatalytic conditions (eq 1). To our delight, the expected 2,3-diphenyl indole 15a was isolated in 60 % yield.…”

mentioning

confidence: 99%

A Visible‐Light‐Mediated Oxidative CN Bond Formation/Aromatization Cascade: Photocatalytic Preparation of N‐Arylindoles

Maity¹,

Zheng²

2012

Angew Chem Int Ed

247

104

View full text Add to dashboard Cite

Indoles: A joint effort of light and air We have developed a mild aerobic oxidation protocol using visible light photocatalysis to synthesize structurally diverse N-arylindoles. The procedure employs 4 mol% [Ru(bpz)3](PF6)2, 18W LED light, and is performed open to the atmosphere. Readily prepared o-stryryl anilines are converted to a variety of indoles via a cascade sequence composed of oxidation of anilines, C-N bond formation, and aromatization. A 1,2-carbon shift can be also incorporated into this cascade event to further extend the substrate scope of the method. bpz = 2, 2′-Bipyrazine

show abstract

“…Because of the paucity of methods to access δ-carbolines, [6] we decided to find the optimal conditions for their construction. After testing a variety of metal complexes, [12] we found that Rh II 2 -carboxylates were unique in their ability to catalyze the conversion of aryl azide 1 into 2 , [13] and the highest yield was attained using 5 mol% of [Rh 2 (esp) 2 ] complex in dichloroethane [Eq. (1)].…”

mentioning

confidence: 99%

Rh^II₂‐Catalyzed Synthesis of α‐, β‐, or δ‐Carbolines from Aryl Azides

2012

View full text Add to dashboard Cite

Approaching all isomers: A range of α‐, β‐ and δ‐carbolinium ions are readily available from ortho‐substituted aryl azides using a rhodium(II) carboxylate catalyst (see scheme). The carbolinium ions are readily reduced to afford tryptolines or deprotonated to access pyridoindoles. This [RhII2]‐catalyzed CH bond amination was used in the synthesis of (±)‐horsfiline and neocryptolepine. esp=α,α,α′,α′‐ tetramethyl‐1,3‐benzenedipropionate.

show abstract

Dirhodium(II)‐Catalyzed Intramolecular CH Amination of Aryl Azides

Abstract: Indole aus Aziden: Die Dirhodium(II)‐katalysierte Zersetzung von Arylaziden macht auf milde Weise Indole zugänglich, ohne dass dabei eventuell vorhandene funktionelle Gruppen stören (siehe Schema).

Cited by 93 publications

References 67 publications

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

A Visible‐Light‐Mediated Oxidative CN Bond Formation/Aromatization Cascade: Photocatalytic Preparation of N‐Arylindoles

Rh^II₂‐Catalyzed Synthesis of α‐, β‐, or δ‐Carbolines from Aryl Azides

Contact Info

Product

Resources

About

Dirhodium(II)‐Catalyzed Intramolecular CH Amination of Aryl Azides

Abstract: Indole aus Aziden: Die Dirhodium(II)‐katalysierte Zersetzung von Arylaziden macht auf milde Weise Indole zugänglich, ohne dass dabei eventuell vorhandene funktionelle Gruppen stören (siehe Schema).

Cited by 93 publications

References 67 publications

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

Selective Intramolecular CH Amination through the Metalloradical Activation of Azides: Synthesis of 1,3‐Diamines under Neutral and Nonoxidative Conditions

A Visible‐Light‐Mediated Oxidative CN Bond Formation/Aromatization Cascade: Photocatalytic Preparation of N‐Arylindoles

RhII2‐Catalyzed Synthesis of α‐, β‐, or δ‐Carbolines from Aryl Azides

Contact Info

Product

Resources

About

Rh^II₂‐Catalyzed Synthesis of α‐, β‐, or δ‐Carbolines from Aryl Azides