The development of a new platform to initiate the cascade rearrangement of furans for the formation of functionalized cyclopentenone building blocks is reported. This methodology allows the creation of congested vicinal stereogenic centers with high diastereoselectivity through a 4π-electrocyclization process.

A novel rhodium-catalyzed linear codimerization of alkyl phenyl ketenes with internal alkynes to dienones and a novel synthesis of furans by an unusual cycloaddition of diaryl ketenes with internal alkynes have been developed. These reactions proceed smoothly with the same rhodium catalyst, RhCl(PPh(3))(3), and are highly dependent on the structure and reactivity of the starting ketenes.

A novel cyclization process of 2,3-bis(trimethylsilyl)buta-1,3-diene with various acyl chlorides in the presence of aluminium trichloride affords 2,5-disubstituted or 2,3,5-trisubstituted furans in short reaction time; a subsequent acylation process of the furan ring occurs if the reaction time is prolonged.

Using Ag2CO3 as an additive, we developed the Pd-catalyzed intermolecular C-H/C-H cross-coupling of pyridine N-oxides with five-membered heterocycles such as 1-benzyl-1,2,3-triazoles, thiophens and furans. This protocol provides an efficient and regioselective approach for the synthesis of unsymmetrical biheteroaryl molecules.

A total of 19 alkylated heterocycles (thiophenes, benzothiophenes, pyrroles, furans) were prepared (36-99% yield) from the respective pyridin-2-yl-substituted precursors employing alkylboronic acids as the C-H alkylating reagents in an oxidative (Ag2CO3 and 2,6-dimethyl-1,4-benzoquinone as oxidants) Pd-catalysed coupling reaction.

A series of ynenyl allyl ethers were rearranged into polysubstituted furans in the presence of a gold(I) catalyst. It is proposed that the transformation involves a Claisen-type rearrangement that allows the efficient creation of quaternary centers under mild experimental conditions.

Ketones with bulky aromatic, heteroaromatic and ferrocene substituents react with acetylene in the presence of a KOH/DMSO super-base suspension (90 °C, 15 min) to give polysubstituted furans in up to 86 % isolated yields in a one-pot fashion. This assembly of the furan scaffold involves a domino sequence in which one molecule of ketone reacts with two molecules of acetylene.

Asymmetric and site-selective formal [3 + 2]-annulations of γ-alkyl-β,γ-unsaturated γ-lactams with α,β-unsaturated aldehydes have been developed. These organocatalysed transformations yield high value enantioenriched bicyclic γ-lactams with up to four new stereocenters (sometimes including a quarternary carbon). The overall transformation starts from simple and readily accessible furans and ove...