Multicomponent reaction of conjugated enynones with malononitrile and sodium alkoxides: Complex reaction mechanism of the formation of pyridine derivatives

Stereoselective Synthesis of Multisubstituted Cyclohexanes by Reaction of Conjugated Enynones with Malononitrile in the Presence of LDA

“…(2RS,3SR,4RS,6SR)-4-Hydroxy-3-(oxophenylmethyl)-4-phenyl-2,6-bis(phenyletynyl)cyclohexane-1,1-dicarbonitrile ( 2a ) [ 3 ]. Obtained from 1a (100 mg, 0.44 mmol) in a yield of 70 mg (60%).…”

“…HRMS (ESI-TOF) m/z : [M + Na] + Calcd for C 37 H 26 N 2 O 2 Na 553.1892; Found 553.1886. X-ray of 2a were given previously [ 3 ].…”

“…1-Cyano-5-phenyl-3-phenylethynyl-5-oxopentannitrile ( 3a ) [ 3 ]. Obtained from 1a (50 mg, 0.22 mmol) and malononitrile 14.5 mg (0.22 mmol) in a yield of 21 mg (32%).…”

“…In our previous work, we studied a multicomponent reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile and sodium alkoxides affording substituted pyridines [ 3 ]. In that study [ 3 ], we showed just one example of the synthesis of multisubstituted cyclohexane by the reaction of 1,5-diphenylpent-2-en-4-yn-1-ones with malononitrile using lithium diisopropylamide (LDA), as a base, instead of sodium alkoxides. We decided to investigate this intriguing reaction deeper.…”

Ketone Derivatives of Propargylamines as Synthetic Equivalents of Conjugated 2,4,1-Enynones in the Synthesis of Acetylenic 2-Pyrazolines and Pyrazoles

“…Conjugated enynones are applied successfully as substrates in the synthesis of various functional derivatives of oxygen-, − nitrogen-, − and sulfur-containing , heterocycles. This can be attributed to the high reactivity of the conjugated π-system and chemical diversity of their reaction centers, as well as the possibility of the presence of enynones in the form of three isomers with different relative positions of multiple bonds (conjugated 2,4,1-, 1,4,3-, and 4,2,1-enynones and 2-methylenebut-3-yn-1-ones). − − …”