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Direct C‐2 Carboxylation of 3‐Substituted Indoles Using a Combined Brønsted Base Consisting of LiO‐<i>t</i>Bu/CsF/18‐crown‐6

https://doi.org/10.1002/ejoc.202000272
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The 74 checked references that resolve
resolves10.1039/b502162f
Simple indole alkaloids and those with a nonrearranged monoterpenoid unit
resolves10.1002/anie.200901843
Catalytic Functionalization of Indoles in a New Dimension
resolves10.1002/ange.200901843
Katalytische Funktionalisierung von Indolen in einer neuen Dimension
resolves10.1021/cr900211p
Marine Indole Alkaloids: Potential New Drug Leads for the Control of Depression and Anxiety
resolves10.1021/jm5000112
Optimization of Chemical Functionalities of Indole-2-carboxamides To Improve Allosteric Parameters for the Cannabinoid Receptor 1 (CB1)
resolves10.1021/jo402593w
Total Synthesis of Ellipticine Quinones, Olivacine, and Calothrixin B
resolves10.1016/j.ejmech.2014.10.065
A review on recent developments of indole-containing antiviral agents
resolves10.1038/ncomms6933
Using carbon dioxide as a building block in organic synthesis
resolves10.1039/c0cs00129e
Transition-metal-catalyzed C–C bond formation through the fixation of carbon dioxide
resolves10.1002/anie.201803186
Transition‐Metal‐Catalyzed Carboxylation Reactions with Carbon Dioxide
resolves10.1002/ange.201803186
Übergangsmetallkatalysierte Carboxylierungen mit Kohlendioxid
resolves10.1039/c3sc51070k
N-Heterocyclic carbene (NHC)–copper-catalysed transformations of carbon dioxide
resolves10.3762/bjoc.14.221
Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source
resolves10.1007/3418_2015_110
Transition Metal-Catalyzed Carboxylation of Organic Substrates with Carbon Dioxide
resolves10.1021/cs300448v
Catalytic C–H Carboxylation of Terminal Alkynes with Carbon Dioxide
resolves10.1007/s11244-014-0301-9
Making C–C Bonds from Carbon Dioxide via Transition-Metal Catalysis
resolves10.1039/C7CC05978G
Chemical reduction of CO <sub>2</sub> facilitated by C-nucleophiles
resolves10.1002/cssc.201700205
Photochemical Carboxylation of Activated C(sp<sup>3</sup>)−H Bonds with CO<sub>2</sub>
resolves10.1002/cssc.201701058
C−H Carboxylation of Aromatic Compounds through CO<sub>2</sub> Fixation
resolves10.1002/cssc.201802012
C−H Bond Carboxylation with Carbon Dioxide
resolves10.1055/s-0036-1588403
CO2 = CO + O: Redox-Neutral Lactamization and Lactonization of C–H Bonds with CO2
resolves10.1002/anie.201007883
Transition‐Metal‐Catalyzed Carboxylation of CH Bonds
resolves10.1002/ange.201007883
Übergangsmetallkatalysierte Carboxylierung von C‐H‐Bindungen
resolves10.6023/cjoc201606007
Recent Advance of Transition Metal-Catalyzed Direct C-H Bond Carboxylation with CO<sub>2</sub>
resolves10.6023/cjoc201701031
Recent Progress in the Cyclization Reactions Using Carbon Dioxide
resolves10.1021/ja01098a035
Metalation of Indole, N-Methylindole and N-Phenylindole with n-Butyllithium<sup>1a</sup>
resolves10.3987/COM-89-4914
The Directed Lithiation of Isogramine and Subsequent Reactions with Electrophiles in the Preparation of 2-Substitutes Isogramine Derivatives
resolves10.1021/jo00959a018
Syntheses with N-protected 2-lithioindoles
resolves10.1016/S0040-4039(00)98265-0
Carbon dioxide: A reagent for the protection of nucleophilic centres and the simultaneous activation of alternative locations to electrophilic attack.
resolves10.1016/S0040-4020(00)01063-2
Selective C-3 and C-2 lithiation of 1-(2,2-diethylbutanoyl)indole
resolves10.1055/s-2008-1078415
6-<i>Exo</i> Cyclizations of 2-Indolylacyl Radicals: Access to the Uleine Alkaloid Skeleton
resolves10.1039/p19960002331
Magnesiation of indoles with magnesium amide bases
resolves10.1002/asia.201403247
Copper‐Catalyzed Formal CH Carboxylation of Aromatic Compounds with Carbon Dioxide through Arylaluminum Intermediates
resolves10.1039/C4CC06188H
Direct carboxylation of simple arenes with CO <sub>2</sub> through a rhodium-catalyzed C–H bond activation
resolves10.1016/S0040-4039(02)01710-0
Selective lithiation of 2,3-dibromo-1-methylindole. A synthesis of 2,3-disubstituted indoles
resolves10.3390/molecules22111952
Halogen–Metal Exchange on Bromoheterocyclics with Substituents Containing an Acidic Proton via Formation of a Magnesium Intermediate
resolves10.1021/ja061232m
Rhodium(I)-Catalyzed Carboxylation of Aryl- and Alkenylboronic Esters with CO<sub>2</sub>
resolves10.1002/anie.200801857
Carboxylation of Organoboronic Esters Catalyzed by N‐Heterocyclic Carbene Copper(I) Complexes
resolves10.1002/ange.200801857
Carboxylation of Organoboronic Esters Catalyzed by N‐Heterocyclic Carbene Copper(I) Complexes
resolves10.1021/acs.orglett.7b02871
Co-Catalyzed Direct Addition of Allylic C(sp<sup>3</sup>)–H Bonds to Ketones
resolves10.1016/j.tet.2016.03.062
Photochromic reaction behavior and thermal stability of thiophene-S,S-dioxidized diarylethenes having a benzofuryl group
resolves10.1021/acs.orglett.6b00918
EtAlCl<sub>2</sub>/2,6-Disubstituted Pyridine-Mediated Carboxylation of Alkenes with Carbon Dioxide
resolves10.1002/chem.201503787
Visible‐Light‐Induced Direct Photocatalytic Carboxylation of Indoles with CBr<sub>4</sub>/MeOH
resolves10.1021/ol101450u
Carbon Dioxide as the C1 Source for Direct C−H Functionalization of Aromatic Heterocycles
resolves10.1039/C6GC00200E
C–H carboxylation of heteroarenes with ambient CO <sub>2</sub>
resolves10.1002/chem.201601114
Carboxylation of Phenols with CO<sub>2</sub> at Atmospheric Pressure
resolves10.1038/nature17185
Carbon dioxide utilization via carbonate-promoted C–H carboxylation
resolves10.1039/C9CC04550C
Kolbe–Schmitt type reaction under ambient conditions mediated by an organic base
resolves10.1021/acs.orglett.6b03601
Transition-Metal-Free Lactonization of sp<sup>2</sup> C–H Bonds with CO<sub>2</sub>
resolves10.1002/anie.201602095
Lactamization of sp<sup>2</sup> C−H Bonds with CO<sub>2</sub>: Transition‐Metal‐Free and Redox‐Neutral
resolves10.1002/ange.201602095
Lactamization of sp<sup>2</sup> C−H Bonds with CO<sub>2</sub>: Transition‐Metal‐Free and Redox‐Neutral
resolves10.1021/ol3025082
Base-Mediated Carboxylation of Unprotected Indole Derivatives with Carbon Dioxide
resolves10.3987/COM-14-S(K)94
Lithium tert-Butoxide-Mediated Carboxylation Reactions of Unprotected Indoles and Pyrroles with Carbon Dioxide
resolves10.1021/ol300958c
Synthesis of 3-Carboxylated Indoles through a Tandem Process Involving Cyclization of 2-Ethynylanilines Followed by CO<sub>2</sub> Fixation in the Absence of Transition Metal Catalysts
resolves10.1021/acs.orglett.6b00884
Cyclic <i>Anti</i>-Azacarboxylation of 2-Alkynylanilines with Carbon Dioxide
resolves10.1002/chem.201805926
Direct Carboxylation of Electron‐Rich Heteroarenes Promoted by LiO‐<i>t</i>Bu with CsF and [18]Crown‐6
resolves10.1021/acs.orglett.9b01386
Double-Carboxylation of Two C–H Bonds in 2-Alkylheteroarenes Using LiO-<i>t</i>-Bu/CsF
resolves10.1039/c2cc35701a
Organocatalytic deprotonative functionalization of C(sp2)–H and C(sp3)–H bonds using in situ generated onium amide bases
resolves10.1016/j.tet.2014.08.054
Use of tetramethylammonium fluoride (TMAF) and alkali metal alkoxides as an activator for catalytic deprotonative functionalization of heteroaromatic C(sp2)–H bonds
resolves10.1039/C4CC02228A
Direct condensation of functionalized sp <sup>3</sup> carbons with formanilides for enamine synthesis using an in situ generated HMDS amide catalyst
resolves10.1021/acs.oprd.8b00247
Catalytic Deprotonative α-Formylation of Heteroarenes by an Amide Base Generated in Situ from Tetramethylammonium Fluoride and Tris(trimethylsilyl)amine
resolves10.1021/acs.orglett.9b00550
Catalytic Amide–Base System of TMAF and N(TMS)<sub>3</sub> for Deprotonative Coupling of Benzylic C(sp<sup>3</sup>)–H Bonds with Carbonyls
resolves10.1002/chem.201901501
Catalytic Alkynylation of Polyfluoroarenes by Amide Base Generated In Situ
resolves10.1248/cpb.c19-00589
Deprotonative Coupling of Pyridines with Aldehydes Catalyzed by an HMDS-Amide Base Generated &lt;i&gt;in Situ&lt;/i&gt;
resolves10.1002/ajoc.201800438
Construction of Biaryl Scaffolds from Iodoarenes and C−H Heteroarenes Using an Amide Base Generated <i>in situ</i> from Aminosilane and Fluoride Anion
resolves10.1248/cpb.c13-00732
&lt;i&gt;In Situ&lt;/i&gt; Protection Methodology in Carbonyl Chemistry
resolves10.1021/ol8019764
Potassium <i>t</i> -Butoxide Alone Can Promote the Biaryl Coupling of Electron-Deficient Nitrogen Heterocycles and Haloarenes
resolves10.1021/cr400274j
Transition-Metal-Free Coupling Reactions
resolves10.1039/c3ra40813b
Recent advances in transition-metal-free direct C–C and C–heteroatom bond forming reactions
resolves10.1246/cl.2012.130
Transition-metal-free Coupling Reactions of Aryl Halides
resolves10.1002/chem.201301583
A Radical Process towards the Development of Transition‐Metal‐Free Aromatic CarbonCarbon Bond‐Forming Reactions
resolves10.1021/acs.orglett.8b01363
Catalytic Lactonization of Unactivated Aryl C–H Bonds with CO<sub>2</sub>: Experimental and Computational Investigation
resolves10.1002/anie.201406103
Catalytic Wittig Reactions of Semi‐ and Nonstabilized Ylides Enabled by Ylide Tuning
resolves10.1002/ange.201406103
Catalytic Wittig Reactions of Semi‐ and Nonstabilized Ylides Enabled by Ylide Tuning
The 5 references without a DOI — listed, not checked
no DOI — not checkedComprehensive Heterocyclic Chemistry III
no DOI — not checkedHeterocyclic chemistry
no DOI — not checkedFor details of solvent effects see Table S1.
no DOI — not checkedIn the case that the solution of3a LiO‐tBu CsF and 18‐crown‐6 in DMI was heated under an Ar atmosphere instead of CO2at 150 °C for 15 h a complex mixture of products was formed.
no DOI — not checked1‐Methyl‐3‐phenylindole and 1‐methylindole were also used as a substrate however which did not yield the desired carboxylated products.
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