A variety of enantioenriched fluorinated 6H-cyclopenta[c]pyridin-6-one bicycles, a scaffold present in several classes of monoterpenic alkaloids with varied biological activity, were synthesized in just five steps starting from simple aldehyde starting materials. The synthesis presented wide functional group tolerance and moderate to high yields and diastereoselectivities, and could be carried out at gram-scale. These products were suitable for further transformations, such as hydrogenation and deprotection of the tert-butyl sulfonyl protecting group.

Enantioenriched fluorinated monoterpenic alkaloid analogues were synthesised, employing a strategy based on the previously undescribed diastereoselective propargylation of fluorinated tert‐butanesulfinyl imines, and subsequent Pauson‐Khand reaction of resulting enyne derivatives, carried out both stoichiometrically and catalytically. The Pauson‐Khand reaction tolerated both substituted alkenes and alkynes, and took place in good yields and diastereoselectivities, even when applied to a gram‐scale synthesis.

The Pauson–Khand reaction (PKR) is one of the key methods for the construction of cyclopentenone derivatives, which can in turn undergo diverse chemical transformations to yield more complex biologically active molecules. Despite the increasing availability of fluorinated building blocks and methodologies to incorporate fluorine in compounds with biological interest, there have been few significant advances focused on the fluoro-Pauson–Khand reaction, both in the inter- and intramolecular versions. Furthermore, the use of vinyl fluorides as olefinic counterparts had been completely overlooked. In this review, we collect the advances both on the stoichiometric and catalytic intermolecular and intramolecular fluoro-Pauson–Khand reaction, with special attention to the PKR of enynes containing a fluoride moiety.

The tetrahydropyridine structure is present in a wide variety of natural and synthetic compounds with interesting pharmacological properties. Therefore, the search for new chemical routes capable of yielding this valuable nitrogen‐containing heterocycle is of utmost interest. Herein, we report the use of the ruthenium‐catalyzed ring‐closing enyne metathesis (RCEYM) and cross enyne metathesis/ring‐closing metathesis (CEYM/RCM) reactions of chiral nitrogen‐containing 1,7‐enynes as an efficient route to synthesize a variety of enantioenriched tetrahydropyridine‐based conjugated 1,3‐dienes. The RCEYM presented wide functional group tolerance and took place in moderate to high yields, with no significant differences when carried out on gram scale. These 1,3‐dienes were suitable for further transformations, such as the Diels–Alder reaction, effectively yielding more complex enantioenriched bicyclic structures.

The addition of propargylmagnesium bromide to fluorinated aromatic sulfinyl imines gave homopropargyl amines with total regio-and diastereoselection. Complete reversal of diastereoselectivity can be achieved in some cases using coordinating (THF) or noncoordinating (DCM) solvents. Substituted propargylic magnesium reagents have been also tested toward fluorinated aryl sulfinyl imines affording chiral homoallenyl amines with good yields and selectivity control. DFT calculations helped to rationalize the origin of the experimental regio-and diastereoselectivities observed in each case.