Palladium-Catalyzed Triple Successive C–H Functionalization: Direct Synthesis of Functionalized Carbazoles from Indoles

Verma, Akhilesh K.; Danodia, Abhinandan K.; Saunthwal, Rakesh K.; Patel, Monika; Choudhary, Deepak

doi:10.1021/acs.orglett.5b01476

Cited by 90 publications

(22 citation statements)

References 62 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both electron-poor and electron-rich alkenes were suitable to be incorporated into the product (Scheme 78). 77 The isolation of the first and second successive oxidative Heck intermediates supports the mechanism through C-H activation of the indole.…”

Section: Review Synthesismentioning

confidence: 73%

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

et al. 2020

View full text Add to dashboard Cite

Palladium-catalyzed domino reactions are advanced tools in achieving various nitrogen-containing heterocycles in an efficient and economical manner due to the reduced number of steps in the process. This review highlights recent advances in domino processes aimed at the synthesis of indole derivatives and polycyclic systems containing the indole nucleus in intra/intra- or intra/intermolecular reactions. In particular, we consider domino processes that involve a double bond in a step of the sequence, which allow the issue of regioselectivity in the cyclization to be faced and overcome. The different sections in this review focus on the synthesis of the indole nucleus and functionalization of the scaffold starting from different substrates that have been identified as activated starting materials, which involve a halogenated moiety or unactivated unsaturated systems. In the former case, the reaction is under Pd(0) catalysis, and in the second case a Pd(II) catalytic species is required and then an oxidant is necessary to reconvert the Pd(0) into the active Pd(II) species. On the other hand, the second method has the advantage that it uses easy available and inexpensive substrates.1 Introduction2 Indole Scaffold Synthesis2.1 Activated Substrates2.2 Unactivated Substrates3 Functionalization of Indole Scaffold3.1 Activated Substrates3.2 Unactivated Substrates4 Conclusions

show abstract

Section: Review Synthesismentioning

confidence: 73%

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The DHR of N-methylindole with butyl acrylate arose in fair yield using PdCl2/PPh3/Cu(OAc)2 in the solvent mixture (Equation (48) (Under these conditions, free (NH) indoles led mainly to annulation products, like those of Equation (61)) [85]. Note that yields may depend on the DMF/DMSO ratio [85]. DMF/DMSO was also the solvent mixture for the catalytic DHR of free (NH) indoles with maleimides (Equation (47)) [84].…”

Section: C3 Alkenylationsmentioning

confidence: 99%

“…DMF/DMSO was also the solvent mixture for the catalytic DHR of free (NH) indoles with maleimides (Equation (47)) [84]. The DHR of N-methylindole with butyl acrylate arose in fair yield using PdCl 2 /PPh 3 /Cu(OAc) 2 in the solvent mixture (Equation (48) (Under these conditions, free (NH) indoles led mainly to annulation products, like those of Equation (61)) [85]. Note that yields may depend on the DMF/DMSO ratio [85].…”

Section: C3 Alkenylationsmentioning

confidence: 99%

Pd-Catalyzed Intermolecular Dehydrogenative Heck Reactions of Five-Membered Heteroarenes

Bras

Мuzart

2020

Catalysts

View full text Add to dashboard Cite

The Pd-mediated cross-coupling of (hetero)arenes with alkenes may be an effective method for the formation of a C–C bond from two C–H bonds. Discovered by Fujiwara and co-workers in 1967, this reaction led to a number of reports that we firstly highlighted in 2011 (review with references till June 2010) and for which, we retained the name “dehydrogenative Heck reaction”. The topic, especially the reactions of five-membered heteroarenes, has been the subject of intensive research over the last ten years. The present review is limited to these dehydrogenative Heck reactions published since 2010, underlining the progress of the procedures.

show abstract

“…Recently, Verma et al [59] performed a novel Pd(II)-catalyzed approach for the direct synthesis of differentially substituted carbazoles from free (NH) indoles 21 via regioselective triple successive oxidative alkenylations. The reaction was catalyzed by PdCl 2 in the presence of Ph 3 P as ligand and 1 equivalent of Cu(OAc) 2 as oxidant in a mixture of DMF/DMSO (5:1) at 100°C for 16 h. The reaction afforded the desired 1,3-disubstituted carbazole 22 and 3-alkenylindole 23, respectively, in 63 and 22 % yields (Scheme 11).…”

Section: Iii213 C2 Vs C3-alkenylation Of Indolesmentioning

confidence: 99%

Oxidative Alkenylation of Fused Bicyclic Heterocycles

Koubachi

Brahmi

Guillaumet³

et al. 2019

Eur J Org Chem

View full text Add to dashboard Cite

The aim of this review is to highlight the advances made in the C–H/C–H functionalization of 5,5‐fused‐heterocyclic systems and 5,6‐fused‐heterocyclic systems such as indoles (C2, C3, C4, and C7 alkenylation), carbazoles, azaindoles, benzofurans, benzothiophenes, enzothiazoles, benzoxazoles, benzimidazoles, imidazopyridines, indolizines, indazoles (C3 and C7 alkenylation), and caffeine. The reports on oxidative alkenylation of 6,6‐fused‐heterocyclic systems including quinoxaline N‐oxides, quinoxalines, quinolones, isoquinolones, quinolines, 1,4‐benzoquinones, benzo[b][1,4]oxazines, benzo[b][1,4]thiazines, chromones, flavones, coumarins, 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones, 1‐(2H)‐phthalazinones, phosphachromones, phosphacoumarins and sulfocoumarins will be also discussed.

show abstract

Palladium-Catalyzed Triple Successive C–H Functionalization: Direct Synthesis of Functionalized Carbazoles from Indoles

Cited by 90 publications

References 62 publications

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

Pd-Catalyzed Intermolecular Dehydrogenative Heck Reactions of Five-Membered Heteroarenes

Oxidative Alkenylation of Fused Bicyclic Heterocycles

Contact Info

Product

Resources

About