The hydroformylation reaction is one of the most intensively explored reactions in the field of homogeneous transition metal catalysis, and many industrial applications are known. However, this atom economical reaction has not been used to its full potential, as many selectivity issues have not been solved. Traditionally, the selectivity is controlled by the ligand that is coordinated to the active metal center. Recently, supramolecular strategies have been demonstrated to provide powerful complementary tools to control activity and selectivity in hydroformylation reactions. In this review, we will highlight these supramolecular strategies. We have organized this paper in sections in which we describe the use of supramolecular bidentate ligands, substrate preorganization by interactions between the substrate and functional groups of the ligands, and hydroformylation catalysis in molecular cages.

Phosphinidenes [R-P] are convenient P building blocks for the synthesis of a plethora of organophosphorus compounds. Thus far, transition-metal-complexed phosphinidenes have been used for their singlet ground-state reactivity to promote selective addition and insertion reactions. One disadvantage of this approach is that after transfer of the P moiety to the substrate, a challenging demetallation step is required to provide the free phosphine. We report a simple method that enables the Lewis acid promoted transfer of phenylphosphinidene, [PhP], from NHC=PPh adducts (NHC=N-heterocyclic carbene) to various substrates to produce directly uncoordinated phosphorus heterocycles that are difficult to obtain otherwise.

Syntheses, properties, and reactivity of N‐heterocyclic carbene–phosphinidene adducts are reviewed. These adducts, formally built by combining a phosphinidene with a carbene, are characterized by high nucleophilicity at the phosphorus atom. The main types of reactivity these adducts exhibit are: Lewis‐base reactivity towards main group and organic compounds as well as transition‐metal complexes, substitution reactions at the phosphorus atom with main group compounds and transition‐metal complexes, and phosphinidene transfer reactions resulting in C–P bond cleavage. These differ substantially from the classic phosphaalkenes.

This study describes the development and understanding of a palladium-catalyzed cross-coupling of fluoroacetamides with boronic acids, under base-free conditions, to selectively give valuable α,α-difluoroketone derivatives. Detailed mechanistic studies were conducted to assess the feasibility of each elementary step, that is, C­(acyl)–N bond oxidative addition, followed by base-free transmetallation and reductive elimination. These investigations allowed the structural characterization of palladium­(II)­fluoroacyl intermediates derived from C–N bond oxidative addition of an amide electrophile. They also revealed the high reactivity of these intermediates for transmetallation with boronic acids without exogenous base. The mechanistic studies also provided a platform to design a practical catalytic protocol for the synthesis of a diversity of α,α-difluoroketones, including CF2H–ketones. Finally, the synthetic potential of this fluoroacylation methodology is highlighted in sequential, orthogonal C–Br and C–N bond functionalization of an α-bromo-α,α-difluoroacetamide with a focus on compounds of potential biological relevance.