Intramolecular Aminocyanation of Alkenes by NCN Bond Cleavage

Pan, Zhongda; Pound, Sarah M.; Rondla, Naveen R.; Douglas, Christopher J.

doi:10.1002/anie.201310983

Cited by 55 publications

(11 citation statements)

References 65 publications

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“…Douglas and co-workers devised a Lewis acid-promoted reaction of alkenes including an N -cyano- N -phenyl- p -toluene sulfonamide group . The reaction with a stoichiometric amount of B(C 6 F 5 ) 3 in toluene at 90 °C afforded the racemic cyanomethyl-substituted indolines and tetrahydroquinolines in high yield.…”

Section: Cyanation Of Unactivated Alkenesmentioning

confidence: 99%

Catalytic Asymmetric Cyanation Reactions

2016

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Catalytic asymmetric cyanations of prochiral unsaturated compounds affording the corresponding nitrile products in high enantiomeric excess (≥90% in general) are summarized in this review. The nucleophilic cyanide addition onto aldehydes, ketones, and imines is promoted by chiral metal complexes and organocatalysts. Recent progress in asymmetric conjugate cyanation of α,β-unsaturated carbonyl compounds is also discussed. The asymmetric cyanation of unactivated alkenes is catalyzed by chiral transition-metal complexes. Current topics of intramolecular carbocyanation and aminocyanation in addition to the traditional hydrocyanation are reviewed.

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Section: Cyanation Of Unactivated Alkenesmentioning

confidence: 99%

Catalytic Asymmetric Cyanation Reactions

2016

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“…Besides, redox-neutral hydrogen transfer processes instead of intramolecular rearrangement (Li et al, 2019;Gandamana et al, 2018;Mavroskoufis et al, 2020;Mori et al, 2018;Kaiser et al, 2019;Tian et al, 2019;Haibach and Seidel, 2014) thereafter took place in our protocol to form the desaturation products (see Note S2 for extended discussion). Moreover, the desaturation product of 2-allyl anilines are prized building blocks for the divergent synthesis of heterocycles through various transformations (Lu et al, 2018;Lin et al, 2017;Wdowik and Chemler, 2017;Jiang et al, 2017;Chemler, 2013;Du et al, 2015;Miyazaki et al, 2014;Pan et al, 2014;Yu et al, 2017). Yet the current methods for the synthesis of these motifs usually took a long synthetic route and with limited substrate scope (Du et al, 2015;Miyazaki et al, 2014;Pan et al, 2014;Yu et al, 2017) (see Note S3 for extended discussion).…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the desaturation product of 2-allyl anilines are prized building blocks for the divergent synthesis of heterocycles through various transformations (Lu et al, 2018;Lin et al, 2017;Wdowik and Chemler, 2017;Jiang et al, 2017;Chemler, 2013;Du et al, 2015;Miyazaki et al, 2014;Pan et al, 2014;Yu et al, 2017). Yet the current methods for the synthesis of these motifs usually took a long synthetic route and with limited substrate scope (Du et al, 2015;Miyazaki et al, 2014;Pan et al, 2014;Yu et al, 2017) (see Note S3 for extended discussion). This method provides a missing link in the synthesis of 2-allyl anilines with high control of the terminal selectivity and broad substrate generality under mild conditions.…”

Section: Resultsmentioning

confidence: 99%

“…To show the synthetic utility of this method, a variety of 5-and 6-membered N-heterocycles have be expeditiously synthesized with these obtained 2-allyl aniline products (Figure 6, see also Methods for further transformations in SI). Catalytic 5-exo-cyclization, which selectively promoted the formation of new C-N bonds in conjunction with vicinal C-CN (Pan et al, 2014), C-Br (Yu et al, 2017), C-O, C-H, or C-S bonds, delivered the corresponding functionalized indolines 10-14 in high yields. In addition, the 6-endo-cyclization products 15 and 16 were smoothly obtained in 70% and 82% yields under catalytic vicinal chlorination and reductive conditions, respectively.…”

Section: Resultsmentioning

confidence: 99%

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Desaturation via Redox-Neutral Hydrogen Transfer Process: Synthesis of 2-Allyl Anilines, Mechanism and Applications

et al. 2020

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An unprecedented desaturation method via redox-neutral hydrogen transfer process has been disclosed under mild conditions for the selective formation of terminal alkene with alkyl diazo compounds and aza-o-QMs. The control experiments and DFT calculations suggest that the visible light was introduced as a key parameter to enhance the reactivity via a radical process in the formation of closed-shell cyclopropane intermediate, followed by a ring opening and redox-neutral hydrogen transfer process to give the desaturated product. The high regioselectivity in this transformation is enabled by the internal amino species as an ancillary group (AG) in the final olefin formation step. This method provides a missing link in the expeditious preparation of synthetically useful 2-allyl anilines with broad substrate generality. Further applications of these generated products in N-heterocycle construction, including 5-and 6-membered rings with structural diversity, have been tactfully explored, which highlight the potential in methodology development and drug discovery.Recently, methods for the site-controlled desaturation via activating the inert C(sp 3 )-H bonds with the assistance of the embedded directing group (DG) or the tethered radical initiator (RI) have achieved great breakthrough (Figure 1B) (

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“…To confirm the mechanism is independent of oxidant, the reaction was repeated in the absence of O 2 resulting in the same reaction outcome and yield. To trace the origin of the cyano group in the benzonitrile product 2a , N -[ 13 C]-cyano- N -phenyl- p -toluenesulfonamide ([ 13 CN]-NCTS) was reacted with 2,4-dimethoxybenzoic acid ( 1a ) under the same conditions and the product 2,4-dimethoxybenzo-[ 13 C]-nitrile ([ 13 C]- 2a ) was indeed isolated in 75% yield (Table , entry 2). LCMS confirmed the isotopic purity of the reagent [ 13 CN]-NCTS was retained in the nitrile product [ 13 C]- 2a , which is critical for labeling synthesis.…”

Section: Resultsmentioning

confidence: 99%

Development of Decarboxylative Cyanation Reactions for C-13/C-14 Carboxylic Acid Labeling Using an Electrophilic Cyanating Reagent

2017

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Degradation-reconstruction approaches for isotope labeling synthesis have been known for their remarkable efficiency, but applications are scarce due to some fundamental limitations of the chemistries developed to date. The decarboxylative cyanation reaction, as a degradation-reconstruction approach, is especially useful in rapid carboxylic acid carbon isotope labeling, however development toward its application as a widespread technique has stalled at the early stages due to numerous limitations which include somewhat narrow applicability. Employing the electrophilic cyanating reagent N-cyano-N-phenyl-p-toluenesulfonamide (NCTS) as the cyano source, efficient decarboxylative cyanation chemistry has been developed for aryl and alkyl carboxylic acids respectively with two rationally designed reaction pathways. The reactions provided good yields of nitrile products from carboxylic acids, with complete retention of isotopic purity from the [CN]-NCTS used. The reaction conditions are relatively mild requiring no oxidant and no excess toxic heavy metal and the reagent [CN]-NCTS is a stable, easy-to-handle crystalline solid that can be prepared quickly and effectively from the readily available [C]-KCN. The following work describes this novel and efficient method for alkyl and aryl carboxylic acid isotopic labeling using a single reagent.

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Intramolecular Aminocyanation of Alkenes by NCN Bond Cleavage

Cited by 55 publications

References 65 publications

Catalytic Asymmetric Cyanation Reactions

Catalytic Asymmetric Cyanation Reactions

Desaturation via Redox-Neutral Hydrogen Transfer Process: Synthesis of 2-Allyl Anilines, Mechanism and Applications

Development of Decarboxylative Cyanation Reactions for C-13/C-14 Carboxylic Acid Labeling Using an Electrophilic Cyanating Reagent

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