Catalytic asymmetric synthesis of chromenes and tetrahydroquinolines via sequential allylic alkylation and intramolecular Heck coupling

Ene reactions of 2-borylated α-methylstyrenes: a practical route to 4-methylenechromanes and derivatives

4-Methylenechromanes were prepared via a three-step process from 2-borylated α-methylstyrenes. This sequence is based on a key glyoxylate-ene reaction catalyzed by scandium(iii) triflate. The resulting γ-hydroxy boronates, which cyclise to seven-membered homologues of benzoxaborole on silica gel, were cleanly oxidized with sodium perborate, and then cyclised under Mitsunobu conditions. Additionally, several further functional transformations of 4-methylenechromanes or their precursors were carried out to illustrate the synthetic potential of these intermediates.

Progress in the Chemistry of Tetrahydroquinolines

Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, being widespread in nature and present in a broad variety of pharmacologically active compounds. This Review summarizes the progress achieved in the chemistry of tetrahydroquinolines, with emphasis on their synthesis, during the period from mid-2010 to early 2018.

Highly efficient asymmetric construction of novel indolines and tetrahydroquinoline derivatives via aza-Barbier/C–N coupling reaction

An efficient approach towards stereoselective synthesis of chiral indolines and tetrahydroquinolines via Zn-mediated allylation of chiral-N-tert-butanesulfinyl imines and intramolecular C–N cross-coupling is described.

Structurally characterized dipalladium(ii)-oxamate metallacyclophanes as efficient catalysts for sustainable Heck and Suzuki reactions in ionic liquids

Dipalladium-oxamate metallacyclophanes were synthesised, structurally characterized and applied in carbon–carbon cross couplings in ionic liquids.

Bis(N-substituted oxamate)palladate(ii) complexes as effective catalysts for sustainable Heck carbon–carbon coupling reactions in n-Bu4NBr as the solvent

Bis(oxamato)palladate(ii) complexes are structurally well-defined precatalysts for the Heck vinylation of aryl halide derivatives inn-Bu₄NBr as benign ionic liquid.

Synthesis of functionalized 2-aryl-4-(indol-3-yl)-4H-chromenes via iodine-catalyzed domino Michael addition-intramolecular cyclization reaction

An efficient synthesis of novel functionalized 2-aryl-4-(indol-3-yl)-4H-chromenes has been developed, in the presence of a catalytic amount of iodine, from easily available starting materials, 2-hydroxychalcone derivatives. Indole, substituted indoles and 7-azaindole are suitable for this transformation. The possible domino Michael addition-intramolecular cyclization reaction mechanism is proposed.

Copper-catalyzed enantioselective allyl-allyl cross-coupling

A Cu(I)-phosphoramidite-based catalytic system that allows asymmetric allyl-allyl cross-coupling with high enantioselectivity is reported. This transformation tolerates a large variety of functionalized substrates. The versatility of this new reaction is illustrated in the catalytic asymmetric synthesis of the Martinelline alkaloids chromene derivative core.