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2,3-Dihydro-1H-inden-1-one derivatives were synthesized by a [5+2−2] decarbonylative cycloaddition of 1H-indene-1,2,3-trione and norbornene via rhodium(I) catalyzed direct carbon–carbon bond cleavage. A catalytic system combining [Rh(COD)Cl]2 (5.0 mol%) and rac-BINAP(10 mol%) ligand was optimal for these transformations. Various functional groups were tolerated under standard reaction conditions. Although the reactions in most of the cases showed no regioselectivity, some substrates with a –OMe, –CN, or strong electron-withdrawing –CF3 group at the 4-position displayed high regioselectivity. [ABSTRACT FROM AUTHOR]

Here, we describe a facile approach for the synthesis of substituted 1‐naphthylamines via three‐component 6‐endo‐dig cyclization of terminal alkynes with 2‐bromoaryl ketones, primary or secondary amines in water under Pd‐free conditions. The Cu(I) catalytic system avoids a fundamental problem related to these substrates, which competitively evolve through 5‐endo‐dig cyclization pathways under metal catalysis. This unique performance unlocks a rapid access to a diverse 1‐naphthylamines library that previously required longer synthetic routes. The synthetic potential of this method was further demonstrated by the gram‐scale synthesis, and the mechanism study showed that the reaction experienced sequential halide exchange, imine‐enamine tautomerization and 6‐endo‐dig cyclization. [ABSTRACT FROM AUTHOR]

Abstract: A highly efficient Pd0‐catalyzed 6‐endo‐trig Heck cyclization reaction has been developed for the construction of 2‐fluoroalkyl quinolines, which are important structural motifs for bioactive molecules. This process offers broad substrate scope, with excellent 6‐endo selectivity, and affords quinoline derivatives in moderate‐to‐excellent yields. [ABSTRACT FROM AUTHOR]

An atom economical highly efficient method has been developed for the synthesis of quinoline and 1,2,3,4-tetrahydroquinoline derivatives from o-nitrotoluenes bearing electron-withdrawing groups and olefins (acrylic esters, acrylonitriles, and methyl acrylates) via a base-catalyzed [2 + 4] cycloaddition. This simple, rapid, and environment- friendly method provides a practical pathway for the synthesis of quinoline and 1,2,3,4-tetrahydroquinoline derivatives. The starting materials are readily available and 37 products were obtained in good to excellent yields. [ABSTRACT FROM AUTHOR]

A highly efficient one-pot procedure for the preparation of substituted quinolines from substituted o-nitrotoluenes with electron-withdrawing groups and olefins (acrylic esters and acrylonitriles) using a cesium catalyst has been developed. A plausible [2+4] cycloaddition mechanism is proposed. This method uses nitroaromatic compounds as the starting materials to give quinoline derivatives in good to high yields under mild conditions with no transition metal catalysis. It provides an atom economical pathway for the synthesis of quinoline derivatives which could be used in industrial processes. [ABSTRACT FROM AUTHOR]