Iron-catalyzed carboazidation of alkenes and alkynes

Xiong, Hai; Ramkumar, Nagarajan; Chiou, Mong‐Feng; Jian, Wujun; Li, Yajun; Su, Ji‐Hu; Zhang, Xinhao; Bao, Hongli

doi:10.1038/s41467-018-07985-2

Cited by 90 publications

(38 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Probably due to the stabilization of the aromatic osmapentalene framework, complex 2 is a highly stable solid that can persist for several months when exposed to air at room temperature or even when heated to 80°C in air for 3 h. The carboazidation of alkynes by azides, for example trimethylsilyl azide, has been extensively explored and reported to afford 1-azidoalkenes, which can be subsequently converted to 2H-azirines. 39,40 Such reactions have not yet been achieved in metal carbyne triple-bond systems. Very recently, we constrained transition-metal carbyne units into a tricyclic ring system and realized the first [3+2] cycloadditions of a late transition-metal carbyne with organic azides.…”

Section: Resultsmentioning

confidence: 99%

Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes

et al. 2021

View full text Add to dashboard Cite

Three-membered unsaturated rings have been widely utilized in organic synthesis due to their inherent highly strained structures. Although much research has been applied to ring-expansion reactions of such strained ring systems, pathways other than [3+2] cycloadditions have rarely been observed in their reactions with alkynes, and to date, no [3+1] cycloadditions of isolated three-membered unsaturated rings with alkynes have been reported. Here we demonstrate an unprecedented [3+1] cycloaddition in which a fused metalla-azirine is used as a template to generate a series of planar CCCCX-type (X = N, O, S) pentadentate carbolong complexes 3-6. A series of substituted alkynes was tested for further exploration of the scope and mechanism for the [3+1] cycloaddition reactions. Complexes 3-6 represent rare examples of planar pentadentate complexes that assemble four π-conjugated fused rings by one bridgehead atom. These novel complexes are thermally stable in air and absorb ultraviolet, visible, and near-infrared light, and thus are potentially applicable in photoelectric devices and pharmaceuticals.

show abstract

Section: Resultsmentioning

confidence: 99%

Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes

et al. 2021

View full text Add to dashboard Cite

show abstract

“…An efficient and general iron catalyzed fluoroalkylation/azidation of carbon-carbon multiple bonds has been reported by Bao and co-workers [127]. The use of fluoroalkyl iodides with catalytic Fe(OTf) 2 , TMS-N 3 , and (TBPB) in DME at room temperature permits the carboazidation of alkenes, dienes, or alkynes systems in moderate to high yields (Scheme 65).…”

Section: Scheme 64 Enantioselective Azidotrifluoromethylation Of Olementioning

confidence: 98%

Transition Metal Catalyzed Azidation Reactions

et al. 2020

View full text Add to dashboard Cite

A wide range of methodologies for the preparation of organic azides has been reported in the literature for many decades, due to their interest as building blocks for different transformations and their applications in biology as well as in materials science. More recently, with the spread of the use of transition metal-catalyzed reactions, new perspectives have also materialized in azidation processes, especially concerning the azidation of C–H bonds and direct difunctionalization of multiple carbon-carbon bonds. In this review, special emphasis will be placed on reactions involving substrates bearing a leaving group, hydroazidation reactions and azidation reactions that proceed with the formation of more than one bond. Further reactions for the preparation of allyl and vinyl azides as well as for azidations involving the opening of a ring complete the classification of the material.

show abstract

“…The transformation of alkynes is a fundamental method that has been widely used in organic synthesis [ 1 , 2 , 3 , 4 , 5 ] to afford ketones [ 6 , 7 ], diketones [ 8 , 9 ], acids and their derivatives [ 10 , 11 , 12 ], alkyl or alkenyl halides [ 13 , 14 ], cycloalkanes or cycloalkenes [ 15 , 16 , 17 ], and nitriles [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], which makes these processes highly appealing in academic research and industrial applications [ 5 ]. Amongst many reactions of the C≡C triple bond, its cleavage is deemed to be one of the most challenging targets and has stimulated new conceptual strategies in the organic community in recent years [ 5 , 10 , 11 , 12 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

Direct Metal-Free Transformation of Alkynes to Nitriles: Computational Evidence for the Precise Reaction Mechanism

Hok

Vianello

2021

IJMS

View full text Add to dashboard Cite

Density functional theory calculations elucidated the precise reaction mechanism for the conversion of diphenylacetylenes into benzonitriles involving the cleavage of the triple C≡C bond, with N-iodosuccinimide (NIS) as an oxidant and trimethylsilyl azide (TMSN3) as a nitrogen donor. The reaction requires six steps with the activation barrier ΔG‡ = 33.5 kcal mol−1 and a highly exergonic reaction free-energy ΔGR = −191.9 kcal mol−1 in MeCN. Reaction profiles agree with several experimental observations, offering evidence for the formation of molecular I2, interpreting the necessity to increase the temperature to finalize the reaction, and revealing thermodynamic aspects allowing higher yields for alkynes with para-electron-donating groups. In addition, the proposed mechanism indicates usefulness of this concept for both internal and terminal alkynes, eliminates the option to replace NIS by its Cl- or Br-analogues, and strongly promotes NaN3 as an alternative to TMSN3. Lastly, our results advise increasing the solvent polarity as another route to advance this metal-free strategy towards more efficient processes.

show abstract

Iron-catalyzed carboazidation of alkenes and alkynes

Cited by 90 publications

References 40 publications

Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes

Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes

Transition Metal Catalyzed Azidation Reactions

Direct Metal-Free Transformation of Alkynes to Nitriles: Computational Evidence for the Precise Reaction Mechanism

Contact Info

Product

Resources

About