Base-promoted 5-exo-dig cyclizations of aza-propargylglycinamides provided N-amino-imidazolin-2-one peptide mimics, which exhibited turn geometry in X-ray crystallographic and NMR spectroscopic analyses. Sonogashira coupling prior to cyclization afforded N-amino-imidazolin-2-ones with diverse 4-position aromatic substituents with potential to serve as Phe and Trp mimics.

Nickel-catalyzed additions of arylboronic acids to alkynes, followed by enantioselective cyclizations of the alkenylnickel species onto tethered ketones or enones, are reported. These reactions are reliant upon the formal anti-carbonickelation of the alkyne, which is postulated to occur by the reversible E/Z isomerization of an alkenylnickel species.

A novel base-promoted cascade reaction of 2-methyl-3-(1-alkynyl)chromones to produce a 3C-xanthone-linked 3C-chromone scaffold has been developed. This tandem process involves multiple reactions such as Michael additions/cyclizations under mild conditions without a transition metal catalyst and inert atmosphere.

Aza-Heck cyclizations initiated by oxidative addition of Pd(0) -catalysts into the N-O bond of N-(pentafluoro-benzoyloxy)sulfonamides are described. These studies, which encompass only the second class of aza-Heck reaction developed to date, provide direct access to diverse N-heterocyclic ring systems.

A base-promoted, microwave-assisted one-pot tandem reaction from simple 3-(1-alkynyl)chromones with 2-halobenzylic nitriles (esters or amides) for the synthesis of novel functional polycyclic chromenones has been developed. This tandem process involves multiple reactions, such as Michael addition and double cyclizations without a transition metal catalyst.

Herein, we describe the synthesis of new functionalized tricyclic and tetracyclic indole derivatives via samarium diiodide induced ketyl cyclizations. The intermediate samarium organyls were either protonated using different proton sources or alkylated with various electrophiles in a highly diastereoselective manner. The obtained products were subjected to further transformations leading to syn...

Toward the mavacurane and akuammilane monoterpene indole alkaloids, we developed divergent oxidative couplings between nucleus (at N1 or C7) C16-malonate of a common tricyclic model related to strictosidine according biosynthetic hypothesis postulated by Hesse Schmid. These cyclizations led selectively formation N1–C16 bond pleiocarpamine C7–C16 strictamine. We were then able obtain scaffold ta...