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A synthetic strategy for the synthesis of substituted thiophenes is described by the one‐pot reaction of indoles with ketene dithioacetals under mild reaction conditions. Promoted by triflic acid (TfOH), the reaction of indoles with the easily available α‐acetyl ketene dithioacetals resulted in the formation of vinylketene dithioacetals via condensation instead of the well known nucleophilic addition‐alkylthio elimination process. In thepresence of CuBr2, vinylketene dithioacetals can cyclize into the corresponding substituted thiophenes. This transformation may benefit from the acidic reaction conditions and the steric effects of the 2‐substituted indoles. [ABSTRACT FROM AUTHOR]

The C−C bond formation via C−S bond activation (disclosed in 2000) has received increasing attention. However, stoichiometric amounts of exogenous thiophilic reagents are generally required as thiolate scavengers. Herein, a new model for the synthesis of 4-aminoquinolines, the copper(II)-catalyzed aerobic oxidative desulfitative 6π cyclization of the readily available N-arylimino ketene N,S-acetals is described. The reaction can proceed efficiently under mild conditions without any exogeneous thiolate scavengers (due to the formation of disulfide as the by-product) to afford diverse 4-aminoquinolines, a privileged structure motif displaying antimalarial activity, with a wide range of functional groups at the C-2 to C-8 positions. [ABSTRACT FROM AUTHOR]

A new strategy, the 1,3-carbothiolation/aromatization, for the synthesis of functionalized (trifluoromethyl)arenes has been developed that enables the regioselective introduction of two different functional groups onto an “aromatic ring” in the meta-position to each other in a single step. [ABSTRACT FROM AUTHOR]

This first formal [3+2] cycloaddition of α-trifluoromethyl-3-indolylmethanol silyl ethers and acyclic ketene dithioacetals furnishes trifluoromethylated cyclopenta[b]indoles. [ABSTRACT FROM AUTHOR]

The polarity reversible nature of azomethine imines as the crucial transformation enables the title reaction sequence to proceed under mild, transition-metal-free conditions. [ABSTRACT FROM AUTHOR]

α-Acidic isocyanidesare versatile reagents in organicsynthesis, especially for the synthesis of five-membered heterocyclesvia [3 + 2]-cycloaddition reactions with activated multiplebonds. In this communication, the first [3 + 3]-cross-cycloadditionof α-acidic isocyanides with 1,3-dipolar azomethine iminesto generate a series of 1,2,4-triazine derivatives with significantregiochemical control under mild catalytic reaction conditionsis described. This new strategy shows that α-acidic isocyanidescan also be taken as potent reagents for the synthesis of six-memberedheterocycles through [3 + 3]-cross-cycloaddition reactionswith 1,3-dipoles. [ABSTRACT FROM AUTHOR]

Die beiden parallelen Alkenoyleinheiten des abgebildeten cyclischen Dithiolans ermöglichen eine [7C+1C] ‐ Anellierung mit Isocyanessigsäureethylester. Somit sind tricyclische Indolizidin ‐ Alkaloide in zwei Stufen durch basekatalysierte [7C+1C] ‐ Anellierung/intramolekulare Cyclisierung mit anschließender Reduktion/Cyclisierung zugänglich. [ABSTRACT FROM AUTHOR]

A series of trifluoromethylated 1,3-dien-3-ols (IV) are synthesized by regiospecific addition of the Ruppert-Prakash reagent to divinyl ketones (I) and transformed into trifluoromethylated cyclopentadienes (V), norbornenes (VII), and fulvenes (IX). [ABSTRACT FROM AUTHOR]

A base-catalyzed tandem Michael addition/intramolecular isocyanide [3 + 2] cycloaddition of ethyl isocyanoacetate and Michael acceptors with tethered carbonyl groups is described. This reaction leads to the formation of fused oxazolines in a highly diastereoselective manner under very mild conditions. [ABSTRACT FROM AUTHOR]

An abstract of the article "[3 + 3]-Cycloaddition Reactions of α-Acidic Isocyanides with 1,3-Dipolar Azomethine Imines" is presented.

The tandem [3 + 2] cycloaddition/intramolecular imidoyl anion trapping strategy is successfully applied for the synthesis of the title compounds from alkenoyl bis(ketene dithioacetals) and tosylmethyl isocyanide. [ABSTRACT FROM AUTHOR]