Indoles In Good Yields Research Articles

ChemInform Abstract: Efficient and Convenient C‐3 Functionalization of Indoles Through Ce(OAc)3/TBHP‐Mediated Oxidative C—H Bond Activation in the Presence of β‐Cyclodextrin.

AbstractThe oxidative C—H activation of indoles (I) with different alkenes and ketones in the presence of Ce(O‐Ac)3 and β‐cyclodextrin as catalytic system proceeds regioselectively in H2O to afford a variety of 3‐substituted indoles in good yields.

ChemInform Abstract: Diastereoselective Mukaiyama Aldol Reaction of (N‐Alkyl) Isatins with 2‐(Trimethylsilyloxy)furan by Using Lanthanum Triflate.

AbstractTitle reaction provides access towards 3‐hydroxy‐3‐(dihydrofuranyl)indoles in good yields and moderate to good diastereoselectivities (up to 90% d.e.).

FeCl 3 as Lewis acid catalyzed one-pot three-component aza-Friedel–Crafts reactions of indoles, aldehydes, and tertiary aromatic amines

A new strategy for the synthesis of 3-diarylmethyl indoles was developed through FeCl 3 as Lewis acid catalyzed three-component aza-Friedel–Crafts reactions of indoles, aldehydes, and tertiary aromatic amines in one-pot. The reactions generated the corresponding 3-diarylmethyl indoles in good yields under mild reaction conditions by using less expensive, readily available, and environmentally benign iron catalyst. It is important to note that the key feature of this reaction is operational simplicity.

A Facile Route to Polysubstituted Indoles via Three-Component Reaction of 2-Ethynylaniline, Sulfonyl Azide, and Nitroolefin

A copper-catalyzed three-component reaction of 2-ethynylaniline, sulfonyl azide, and nitroolefin is reported. This reaction generates functionalized indoles in good yields and proceeds smoothly under mild conditions. Some hits as an HCT-116 inhibitor are found from the preliminary biological screening.

ChemInform Abstract: Direct C2‐Trifluoromethylation of Indole Derivatives Catalyzed by Copper Acetate.

Abstract Direct C2-selective trifluoromethylation of indole derivatives was achieved with Togni’s hypervalent iodine reagent and CuOAc as a catalyst in MeOH under mild conditions, affording the desired C2-trifluoromethylated indoles in good yield (up to 90%).

ChemInform Abstract: Anhydrous CeCl3‐Catalyzed C3‐Selective Propargylation of Indoles with Tertiary Alcohols.

Anhydrous CeCl3 was successfully used as catalyst for the synthesis of several 3-propargyl indoles in good yields through the reaction of indole with propargyl alcohols in nitromethane.

Brønsted acid catalyzed Diels–Alder reactions of 2-vinylindoles and 3-nitrocoumarins: an expedient synthesis of coumarin-fused tetrahydrocarbazoles

A Brønsted acid catalyzed Diels–Alder reaction of 2-vinylindoles and 3-nitrocoumarins has been described. The methodology allows a rapid and expedient synthesis of a variety of coumarin-fused polycyclic indoles in good yields (up to 82%) with high diastereoselectivities (up to >19:1).

Direct C2-trifluoromethylation of indole derivatives catalyzed by copper acetate

Direct C2-selective trifluoromethylation of indole derivatives was achieved with Togni’s hypervalent iodine reagent and CuOAc as a catalyst in MeOH under mild conditions, affording the desired C2-trifluoromethylated indoles in good yield (up to 90%).

Synthesis of Substituted Indoles from 2-Azidoacrylates and ortho-Silyl Aryltriflates

2-Azidoacrylates react with benzynes in the presence of PPh(3) and CsF to afford substituted indoles in good yields. The reaction involves the formation of iminophosphorane and benzyne and a subsequent double cyclization/hydrolysis/air-oxidation cascade. This methodology was utilized to synthesize 10H-indolo[1,2-a]indol-10-ones.

Anhydrous CeCl 3 catalyzed C3-selective propargylation of indoles with tertiary alcohols

Anhydrous CeCl 3 was successfully used as catalyst for the synthesis of several 3-propargyl indoles in good yields through the reaction of indole with propargyl alcohols in nitromethane.

Three-Component One-Pot Synthesis of 3-(2-Furanyl)indoles from Acetylenedicarboxylate, Isocyanide, and 3-Formylindole

The zwitterions derived from isocyanide and dimethyl acetylenedicarboxylate undergo smooth condensation with 3-formylindoles in benzene at room temperature to give the corresponding 3-(2-furanyl)indoles in good yields. This method provides a simple and convenient route to produce a wide range of 3-heteroarylindoles in a one-pot operation.

ChemInform Abstract: Ruthenium-Catalyzed Synthesis of Indoles from Anilines and Trialkanolammonium Chlorides in an Aqueous Medium.

Abstract Anilines react with trialkanolammonium chlorides in an aqueous medium (H 2 O–dioxane) at 180°C in the presence of a catalytic amount of ruthenium(III) chloride hydrate and triphenylphosphine together with tin(II) chloride dihydrate to afford the corresponding indoles in good yields.

Formal Inverse Sonogashira Reaction: Direct Alkynylation of Arenes and Heterocycles with Alkynyl Halides

Formal Inverse Sonogashira Reaction: Direct Alkynylation of Arenes and Heterocycles with Alkynyl Halides

DDQ-mediated oxidative cross-coupling between propargylic sp 3 and indoles sp 2 carbons

DDQ-catalyzed oxidative cross-coupling reaction between indoles and propargyl compounds is reported for the first time. The reaction involves direct carbon–carbon bond formation between sp 2 carbons of indoles and sp 3 carbons of propargylates to yield the corresponding propargyl indoles in good yields with high selectivity.

Novel method for synthesis of aryl hydrazones from α-diazo esters: scope and limitations of nucleophiles

Aryl hydrazones, the precursor of Fischer indole synthesis, were easily obtained by nucleophilic addition of aryllithium reagents to diazo esters. The aryl hydrazones were converted into indoles in good yields by heating with thionyl chloride in alcohol. Grignard reagent was also a good nucleophile, whereas organozinc reagent did not react with diazo esters. Aryllithium reagents were prepared by reacting aryl bromides having various substitutions at 2-, 3-, 4-, or multi positions with n-BuLi. The addition of nucleophiles derived from bromopyridines to diazo esters also gave hydrazones.

One-Step Synthesis of [1,2]Diazepino[4,5-b]indole Derivatives from the Reaction of Pyranoindolones with Methylhydrazine

The synthesis of a number of [1,2]diazepino[4,5-b]indoles in good yields by a one-step sequence from the reaction of pyranoindolones with methylhydrazine is described. The observed regioselectivity of the reaction is explained considering several reaction paths.

Sonogashira/ N-acyliminium ion aromatic π-cyclisation processes: access to tetra- and pentacyclic lactams

Application of the Sonogashira reaction of N-alkynylimides with 2-iodophenol or 2-iodo- N-tosylaniline affords 2-( N-alkylimino)-benzofurans and indoles in good yield. Selective partial reduction of the latter followed by treatment with TsOH generates N-acyliminium ions, which cyclise to afford tetra- and pentacyclic lactams in good yield. The latter are reduced to the analogous cyclic amines by BH 3.

Regioselective Pd-catalyzed indolization of 2-bromoanilines with internal alkynes using phosphine-free ligands

The possibility of using phosphine-free ligands to promote Pd-catalyzed indolization of 2-bromoanilines with internal alkynes was examined for the first time. Phenylurea was found to be the optimal ligand, which could mediate the synthesis of 2,3-disubstituted indoles in good yields (ca. 60–85%) with high regioselectivity.

Synthesis of 3-(2-N,N-diethylaminoethoxy)indoles as potential 5-HT6 receptor ligands

The synthesis of new pharmaceutically interesting 3-(2-N,N-diethylaminoethoxy)indole derivatives is described. Starting from 3-silyloxy-2-methylindoles, deprotection and in situ aminoalkylation provided 3-(2-N,N-diethylaminoethoxy)indoles in good yield. Further sulfonylation of these novel indoles gave access to potential 5-HT(6) receptor ligands.

Remarkable Effect of N-Substituent on Enantioselective Ruthenium-Catalyzed Propargylation of Indoles with Propargylic Alcohols

Ruthenium-catalyzed enantioselective propargylation of indoles with propargylic alcohols affords the corresponding beta-propargylated indoles in good yields with a high enantioselectivity (up to 95% ee). A remarkable effect of the nature of the N-substituent of indoles is observed for the enantioselectivity of the propargylated indoles. The preparative method described in this paper may provide a novel protocol for asymmetric Friedel-Crafts alkylation of indoles using propargylic alcohols as a new type of electrophiles.