A metal-free one-pot cascade synthesis of highly functionalized biaryl-2-carbaldehydes

Abstract

A metal-free one-pot cascade annulation of acyclic substrates dienaminodioate, cinnamaldehydes and allyl amine was achieved for the synthesis of polyfunctional biaryl-2-carbaldehydes. The reaction proceeds at room temperature by a trifluoroacetic acid mediated Diels-Alder pathway. Synthetic applications of the resulting biaryl-2-carbaldehyde have been demonstrated by conversion into an array of diverse molecules with biological and materials chemistry relevance. The present work offers a complementary route to the existing metal mediated cross-coupling methods for the preparation of biaryls.

Synthesis of 2,3-Dihydro-4-pyridones and 4-Pyridones by the Cyclization Reaction of Ester-Tethered Enaminones

“…It should be noted that compounds of structure 4 were used as substrates for cyclization reactions that yielded biaryl-2-carbaldehydes, 1,2-dihydropyridines, 2-pyridinones, and pyrroles, and we recently reported metal-free and solvent-free conditions for their synthesis from aliphatic amines and weakly nucleophilic aromatic amines . However, structure 1 is less common.…”

Synthesis of 1H‐Inden‐1‐ylidenes via Carboannulation of Internal Alkynes with (E)‐3‐(2‐Bromophenyl) Acrylaldehyde: Potential Precursors for Drug Development

“…Column chromatography were carried out using 60–120 mesh silica gel. ( E )‐3‐(2‐Bromophenyl) acrylaldehyde and derivatives were prepared using the literature procedures . (Triphenylphosphoranylidene) acetaldehyde, 2‐Bromobenzaldehyde, 2‐Bromo‐4‐methylbenzaldehyde, 2‐Bromo‐4‐chlorobenzaldehyde, 5‐Bromo‐1,3‐benzodioxole‐4‐carbaldeh‐yde and 2‐Bromo‐6‐fluorobenzaldehyde were purchased from Sigma‐Aldrich.…”

Organocatalytic Enantioselective Synthesis of Trifluoromethyl‐Containing Tetralin Derivatives by Sequential (Hetero)Michael Reaction–Intramolecular Nitrone Cycloaddition

“…The solid reagents were dried together under reduced pressure before being used. 2‐Bromocinnamaldehyde 1a (1.0 equiv., 1.5 mmol), prepared from the corresponding 2‐bromobenzaldehyde by a literature procedure, was dissolved in THF (0.3 M) and then added to the vial, which was subsequently sealed and heated by microwave irradiation at 100 °C for 2 h. The reaction mixture was cooled to room temperature, opened, filtered through Celite and concentrated under reduced pressure. The residue obtained was purified by flash chromatography [ n ‐hexane‐EtOAc (20:1)].…”