Silver and platinum-catalysed addition of O–H and N–H bonds to allenes

Abstract

5Transition-metal catalysed nucleophile addition to allenes is a very powerful tool for the synthesis of functionalised molecules containing heteroatoms, heterocycles in the intramolecular version, or allyl derivatives in the intermolecular. The reaction has been explored with a wide variety of metals, being silver one of the most effective. Although platinum has somehow been less explored, different reactivity has been observed with this metal, showing the great potential and versatility of this methodology. This 10 review will highlight the reactions with these two metals, silver and platinum, when oxygen or nitrogen nucleophiles are employed. Although most of the examples describe the intramolecular version, some intermolecular reactions have been described with platinum, and will also be covered.

Hydroarylation of N‐Allenyl Derivatives Catalyzed by Copper**

“…Allylic or vinylic molecules are highly valuable intermediates [ 1 ] which are easy‐to‐prepare through transition metal‐catalyzed hydrofunctionalization of monosubstituted allenes. [ 2–4 ] This atom economical strategy usually occurs without any prefunctionalization and with very high chemo‐, regio‐ and stereospecificity. Hydrofunctionalization of allenes mainly allowed the selective formation of C–N, C–O, and C–C bond.…”

Polycyclic Compounds from Allenes via Palladium-Mediated Intramolecular Carbopalladation/Nucleophilic Substitution Cascade Processes

“…[18][19][20][21] Amongst the chemical transformations of allenes, transition-metal-promoted reactions are of particular interest. [22][23][24][25][26][27][28][29][30][31] Generally, transition-metal derivatives can react with allenes in two ways: As a Lewis acid they can coordinate either double bond, usually the less hindered one, and activate it for further transformations, or, upon coordination, carbometallation can occur creating a novel organometallic species that can undergo further transformations. Regarding the first pathway, a large number of structures have been reported where the allene acts as an η 2 ligand (Scheme 1, structure a), however, the substituents can significantly influence the shape of the intermediate, which can have several other forms (Scheme 1, structures b, c and d), as exemplified by well-studied Au species.…”

Unravelling mechanistic insights in the platinum-catalysed dihydroalkoxylation of allenes

“…Transition metal catalysed reaction of allenes [26][27][28][29][30][31][32][33][34] with nucleophiles is one of the most representative examples where the choice of metal has profound implications in the outcome and selectivity, including enantioselectivity, of the reaction [35][36][37][38][39][40][41][42]. For example, the intermolecular reaction of allenes with palladium or gold catalysts in the presence of oxygen nucleophiles gives allyl ethers with the regioselectivity of the addition controlled by the substitution on the allene and the reaction conditions (Scheme 1a and b) [43][44][45][46][47][48][49][50][51][52].…”