Efficient synthesis of functionalized chromones via a two-base mediated formal [3+3] cycloaddition

Ketones as strategic building blocks for the synthesis of natural product-inspired compounds

Natural product-inspired compound collections serve as excellent sources for the identification of new bioactive compounds to treat disease. However, such compounds must necessarily be more structurally-enriched than traditional screening compounds, therefore inventive synthetic strategies and reliable methods are needed to prepare them. Amongst the various possible starting materials that could be considered for the synthesis of natural product-inspired compounds, ketones can be especially valuable due to the vast variety of complexity-building synthetic transformations that they can take part in, their high prevalence as commercial building blocks, and relative ease of synthesis. With a view towards developing a unified synthetic strategy for the preparation of next generation bioactive compound collections, this review considers whether ketones could serve as general precursors in this regard, and summarises the opulence of synthetic transformations available for the annulation of natural product ring-systems to ketone starting materials.

Synthesis of 3-(2-quinolyl) chromones from ynones and quinoline N-oxides via tandem reactions under transition metal- and additive-free conditions

The synthesis of 3-(2-quinolyl) chromones from ynones and quinoline N-oxides via a sequential [3+2] cycloaddition/ring-opening/O-arylation reaction under transition metal- and additive-free conditions is reported.

One-pot synthesis of 3-fluoroflavones via 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-diones and selectfluor at room temperature

An efficient one-pot synthesis of 3-fluoroflavones by the fluorination of 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-diones with selectfluor followed by cyclization and dehydration in the presence of a trace amount of conc. H₂SO₄ at room temperature was developed.