Carbometallation Reactions

Palladium-Catalyzed anti-Carbosilylation of Alkynes to Access Isoquinolinone-Containing Exocyclic Vinylsilanes

“…Carbopalladation of alkynes is an essential synthetic process, because it allows easy access to versatile vinylpalladium species, which can be utilized to synthesize multisubstituted alkenes . In this context, intramolecular carbopalladation of alkyne-tethered aryl halides is particularly intriguing, because it provides a facile and efficient method to access complex cyclic natural products, pharmaceuticals and functional materials .…”

Pd-Catalyzed Cyanoselenylation of Internal Alkynes: Access to Tetrasubstituted Selenoenol Ethers

“…Chemists continue to intensify their research in this field . Various methods have been developed to simplify the synthetic access to different substitution patterns. , In particular, Pd-catalyzed reactions, because of their generality and tolerance toward many functional groups, are a powerful tool to release the inherent reactivity of triple bonds . For example, Larock published a regio- and stereoselective route to triphenylethylene derivatives that are parent compounds of some nonsteroidal drugs .…”

Synthesis of Highly Substituted Furans by a Cascade of Formal anti-Carbopalladation/Hydroxylation and Elimination

“…Furthermore, we showed that by a slight variation of the starting material from tertiary alcohols to cyclopropanols, ketones can be accessed in a cascade reaction (Scheme , eq 2) . Since common carbopalladation reactions lead to a syn -attack on the alkyne unit, − a special substrate and ligand design was required to achieve the crucial cis–trans -isomerization in the coordination sphere of Pd. − The key step was the use of a terminating substituent (e.g., thioethers, tert -butyl, trimethylsilyl) at the alkyne, which must be incapable of β-hydride elimination and a sterically encumbered phosphine ligand that facilitates the generation of a 14 VE (valence electron) complex. By computational means, the latter was shown to be the decisive intermediate for the anticipated isomerization.…”