Three‐Component Synthesis of Cryofluorescent 2,4‐Disubstituted 3H‐1,5‐Benzodiazepines – Conformational Control of ­Emission Properties

Abstract

Keywords: Benzodiazepines / C-C coupling / Cyclocondensation / Fluorescence / Microwave-assisted reactions / Multicomponent reactions 2,4-Disubstituted benzodiazepines are readily synthesized in good yields from acyl chlorides, terminal alkynes, and benzene-1,2-diamines by a consecutive one-pot, three-component Sonogashira coupling/Michael addition/cyclocondensation sequence. These diazepines display intense solid-state fluorescence, but only weak emission in solution at room temperature. The absorption and emission maxima can be controlled by the substitution pattern. Upon cooling, how-

Regiospecific Three‐Component Access to Fluorescent 2,4‐Disubstituted Quinolines via One‐Pot Coupling‐Addition‐Cyclocondensation‐Sulfur Extrusion Sequence

“…1 H NMR (500 MHz, CDCl 3 ): δ = 1.41 (s, 9 H, CMe 3 ), 7.14 (dd, 3 [13] According to the GP 4l was obtained as yellow solid; m.p. 158°C.…”

“…[11] Based upon this facile catalytic access to alkynones under mild conditions we could establish a general diversity-oriented access to many classes of heterocycles based upon multi-component reactions that proceed in the sense of consecutive one-pot coupling-addition-cyclocondensation or coupling-cycloaddition sequences. [13] The analogous reaction with 2-aminothiophenols as dinucleophiles leads to a three-component access to benzo-[b] [1,5]thiazepines. [13] The analogous reaction with 2-aminothiophenols as dinucleophiles leads to a three-component access to benzo-[b] [1,5]thiazepines.…”

Microwave-Assisted Syntheses of Bioactive Seven-Membered, Macro-Sized Heterocycles and Their Fused Derivatives

“…Final products are obtained in approximately 70% yield (two steps, Scheme 20). Willy and co-workers [49] have synthesized 2,4-disubstituted benzodiazepines 107 in good yields from acyl chlorides 105, alkynes 106, and benzene-1,2-diamines (o-phenylenediamines) by a consecutive one-pot, three-component Sonogashira coupling/Michael addition/cyclocondensation sequence. These diazepines display intense solid-state fluorescence, but only weak emission in solution at room temperature.…”

Metal-free synthesis of ynones via direct C–H alkynylation of aldehydes with ethynylbenziodoxolones

“…1 More importantly, they are often employed as important key intermediates in the organic synthesis. They are precursors to valuable organic functional groups, such as pyrimidines, 2 quinolones, 3 furans, 4 pyrazoles, 5 pyrroles, 6 isoxazoles, 7 benzodiazepines, 8 flavones, 9 oximes, 10 chiral propargylic alcohols. 11 Therefore, developing new strategies for the synthesis of ynones is of significance.…”