Copper‐Catalyzed Enantioselective Cyano(Fluoro)Alkylation of Alkenes

Israr, Muhammad; Xiong, Hai; Li, Yajun; Bao, Hongli

doi:10.1002/adsc.202000230

Cited by 26 publications

(9 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A complementary method has been recently disclosed by Bao and co-workers . The authors used the primary radical obtained from the reduction of lauroyl peroxide by CuTc (copper thiophene-2-carboxylate) as relay to produce the perfluoroalkyl radical via iodine atom transfer from the corresponding iodide in association with TMSCN and the same chiral BOX ligand.…”

Section: Chiral Transition-metal-catalyzed Asymmetric Radical Processesmentioning

confidence: 97%

“…A complementary method has been recently disclosed by Bao and co-workers. 462 The authors used the primary radical obtained from the reduction of lauroyl peroxide by CuTc (copper thiophene-2-carboxylate) as relay to produce the perfluoroalkyl radical via iodine atom transfer from the corresponding iodide in association with TMSCN and the same chiral BOX ligand. The enantioselective trifluoroamination of alkenes bearing different aryl groups was achieved by means of Cu(I)/chiral phosphoric acid (CPA) cooperative catalysis using hydrazides and Togni-I reagent (Scheme 205).…”

Section: Cascade Involving Addition To Alkenesmentioning

confidence: 99%

See 1 more Smart Citation

Enantioselective Radical Reactions Using Chiral Catalysts

Mondal¹,

et al. 2022

View full text Add to dashboard Cite

Scheme 24 Enantioselective Radical Hydroacylation of Enals with α-Ketoacids byMerging Photoredox Catalysis with Amine Catalysis.Jang et al. exploited enantioselective tandem Michael addition/oxyamination of α,β-unsaturated aldehydes by combining asymmetric iminium catalysis using organocatalyst with photoinduced SOMO catalysis using N719/TiO2. 60 Here, TiO2 acts as a second cooperative photocatalyst along with Ru photocatalyst N719 which bound to the latter, increases the enantio-and diastereoselectivity of the process. Adamantane carboxylic acid (30 mol%) was used as an additive which promotes formation of iminium ion 2.1.48A from aldehyde 2.1.48 and chiral amine catalyst. This iminium intermediate then reacts with diethyl malonate to provide intermediate 2.1.48B which either undergoes hydrolysis to form β-substituted aldehyde 2.1.50 or photo-oxidation by the photoexcited Ru(II) dye to form enamine radical 2.1.48C. Subsequent addition of TEMPO to radical intermediate 2.1.48BC followed by hydrolysis afforded the desired product 2.1.49 (Scheme 25). This mechanism is obeying to a polar/radical crossover sequence where the first stereocontrol arises from the addition of the malonate.Recently, Bach group reported promising preliminary results of enantioselective [2+2] photocycloaddition of cinnamaldehyde in the presence of ruthenium photocatalyst and proline derived organocatalyst. 61

show abstract

Section: Chiral Transition-metal-catalyzed Asymmetric Radical Processesmentioning

confidence: 97%

Section: Cascade Involving Addition To Alkenesmentioning

confidence: 99%

Enantioselective Radical Reactions Using Chiral Catalysts

Mondal¹,

et al. 2022

View full text Add to dashboard Cite

show abstract

“…In their work, benzylic radicals, generated by intermolecular hydrogen atom transfer, could be enantioselectively cyanated by applying a chiral bisoxazoline (BOX)-copper catalyst and TMSCN as the cyanide source (Scheme A). This valuable strategy was found to be also applicable to related systems. − All these reports deal with the trapping of prochiral secondary benzylic radicals, where radical generation is achieved by C(sp 3 )–H-atom abstraction, , β-addition to styrenes, − or by C–C-bond cleavage. , In addition, merging photo- or electrocatalysis with Cu-catalysis has further broadened the scope of such radical transformations. − …”

Section: Introductionmentioning

confidence: 99%

Enantioselective Copper-Catalyzed Fukuyama Indole Synthesis from 2-Vinylphenyl Isocyanides

et al. 2023

View full text Add to dashboard Cite

Enantioenriched chiral indoles are of high interest for the pharmaceutical and agrochemical industries. Herein, we present an asymmetric Fukuyama indole synthesis through a mild and efficient radical cascade reaction to access 2-fluoroalkylated 3-(α-cyanobenzylated) indoles by stereochemical control with a chiral copper-bisoxazoline complex using 2-vinylphenyl arylisocyanides as radical acceptors and fluoroalkyl iodides as C-radical precursors. Radical addition to the isonitrile moiety, 5-exo-trig cyclization, and Cu-catalyzed stereoselective cyanation provide the targeted indoles with excellent enantioselectivity and good yields. Due to the similar electronic and steric properties of the two aryl substituents to be differentiated, the enantioselective construction of the cyano diaryl methane stereocenter is highly challenging. Mechanistic studies reveal a negative nonlinear effect which allows proposing a model to explain the stereochemical outcome. Scalability and potential utility of the enantioenriched 3-(α-cyanobenzylated) indoles as hubs for chiral tryptamines, indole-3-acetic acid derivatives, and triarylmethanes are demonstrated, and a formal synthesis of a natural product analogue is disclosed.

show abstract

“…12 All of these reactions are very efficient for the incorporation of both CF 3 and CN groups, and some processes have been extended to other fluoroalkyl groups, such as C 4 F 9 and CF 2 CO 2 Et. 13 However, compared to trifluoromethylation, perfluoroalkylation and difluoroalkylation, the analogous monofluoroalkylation of alkenes has rarely been investigated. In particular, the copper-catalyzed monofluoroalkylation of alkenes with the concomitant introduction of an additional useful functionality group (such as CN) is underexplored.…”

Section: Introductionmentioning

confidence: 99%