Graphene Oxide Promotes Site-Selective Allylic Alkylation of Thiophenes with Alcohols

The graphene oxide (GO) assisted allylic alkylation of thiophenes with alcohols is presented. Mild reaction conditions and a low GO loading enabled the isolation of a range of densely functionalized thienyl and bithienyl compounds in moderate to high yields (up to 90%). The cooperative action of the Bronsted acidity, epoxide moieties, and pi-surface of the 2D-promoter is highlighted as crucial in the reaction course of the present Friedel-Crafts-type protocol

Efficient Guanidine-Catalyzed Alkylation of Indoles with Fluoromethyl Ketones in the presence of Water

A simple and efficient guanidine-catalyzed methodology for the direct preparation of trifluoromethyl-indolyl-phenylethanols in the presence of water is reported. This synthetically viable class of compounds is obtained in excellent yields (up to 98%) through Friedel−Crafts-type alkylation of indoles with aromatic fluoromethyl ketones. Exceptional reaction scope of indoles and alkylating agents is described

Efficient Guanidine-Catalyzed Alkylation of Indoles with Fluoromethyl Ketones in the presence of Water

A simple and efficient guanidine-catalyzed methodology for the direct preparation of trifluoromethyl-indolyl-phenylethanols in the presence of water is reported. This synthetically viable class of compounds is obtained in excellent yields (up to 98%) through Friedel−Crafts-type alkylation of indoles with aromatic fluoromethyl ketones. Exceptional reaction scope of indoles and alkylating agents is described

Regio- and Stereoselective Electrochemical Alkylation of Morita–Baylis–Hillman Adducts

Electrosynthesis is effectively employed in a general regio- and stereoselective alkylation of Morita–Baylis–Hillman compounds. The exposition of N-acyloxyphthalimides (redox-active esters) to galvanostatic electroreductive conditions, following the sacrificial-anode strategy, is proved an efficient and practical method to access densely functionalized cinnamate and oxindole derivatives. High yields (up to 80%) and wide functional group tolerance characterized the methodology. A tentative mechanistic sketch is proposed based on dedicated control experiments

New Versatile Pd-Catalyzed Alkylation of Indoles via Nucleophilic Allylic Substitution: Controlling the Regioselectivity

A systematic study addressed toward the optimization of the Pd-catalyzed alkylation of indoles by allylic carbonates is presented. The protocol uses a catalytic amount of [PdCl(π-allyl)]2/phosphine as a promoting agent, providing allylindoles in excellent yields. The regioselectivity of the reaction can be controlled by a proper choice of the base and the reaction media. The method proved to be effective also for intramolecular allylic alkylations of indolyl carbonates, providing a flexible route to fused indole alkaloids

PPh₃AuTFA Catalyzed in the Dearomatization of 2‑Naphthols with Allenamides

A new catalytic methodology for the direct dearomatization of substituted 2-naphthols via intermolecular condensation with allenamides is presented. PPh3AuTFA (5 mol %) promotes the formal allylating dearomative protocol under mild conditions, large scope (24 examples), and high regioselectivity and stereoselectivity. The synergistic catalytic role played by the [PPh3Au]+ (π-acid) and TFA– (Lewis base) is highlighted

New Versatile Route to the Synthesis of Tetrahydro-β-carbolines and Tetrahydro-pyrano[3,4-<i>b</i>]indoles via an Intramolecular Michael Addition Catalyzed by InBr₃

A simple multistep synthetic strategy to 4-substituted 1,2,3,4-tetrahydro-β-carboline and 1,3,4,9-tetrahydro-pyrano[3,4-b]indole derivatives starting from commercially available indole 2-carboxylic acid (5) is described. The final intramolecular Michael addition promoted by catalytic amount of InBr3 (5−10 mol %) provided the expected polycyclic compounds in excellent yields (up to 97%) both in anhydrous organic and aqueous media

Enantioselective Gold-Catalyzed Synthesis of Polycyclic Indolines

The synthesis of architecturally complex polycyclic fused indolines is achieved in a chemo-, regio-, and stereodefined manner, via an enantioselective gold-catalyzed cascade hydroindolination/iminium trapping synthetic sequence. Highly functionalized tetracyclic fused furoindolines (<b>2</b>) and dihydropyranylindolines (<b>4</b>) are synthesized in moderate to good yields and enantiomeric excesses of up to 87%

InBr₃-Catalyzed Friedel−Crafts Addition of Indoles to Chiral Aromatic Epoxides: A Facile Route to Enantiopure Indolyl Derivatives

Aromatic optically active epoxides can be opened in a regioselective and clean way with indoles in the presence of catalytic amount of InBr3 (1 mol %). The reaction takes place with a SN2 pathway affording the 2-aryl-2-(3‘-indolyl)ethan-1-ols with excellent enantioselectivity (ee up to 99%)