Selective Selenocatalytic Allylic Chlorination.

Solid-phase selenium-catalyzed selective allylic chlorination of polyprenoids: facile syntheses of biologically active terpenoids.

Regioselective halogenation of the terminal isopropylidene unit of different acyclic polyolefinic polyprenoids (farnesyl acetate, geranylgeranyl acetate, squalene, etc.) using NCS/catalytic polymer-supported selenenyl bromide is described; good to excellent yields are obtained (68-96%). The first applications of this protocol include the concise synthesis of bioactive terpenoids 1-3.

Iridium-Catalyzed 1,3-Hydrogen Shift/Chlorination of Allylic Alcohols**

Chlorinated compounds are among the most common and versatile building blocks in organic synthesis. Among these, achlorocarbonyl derivatives are of synthetic value owing to the variety of functional groups that can be introduced both at the chlorinated a-carbon atom and at the carbonyl functionality. For instance, they readily undergo substitution/addition reactions and cross-coupling reactions...

Ruthenium catalysts for selective nucleophilic allylic substitution*

Recent developments in the chemistry of η3-allylruthenium(IV) complexes are due to their straightforward synthesis resulting from oxidative addition of allylic substrates to a ruthenium(II) center. Subsequent reaction with a nucleophile is the basis of their involvement in the catalytic allylic substitution reaction. We focus here on ruthenium-catalyzed substitution of allylic substrates by C-,...

Palladium-catalyzed selective anti-Markovnikov oxidation of allylic esters.

Switchable Site-Selective Catalytic Carboxylation of Allylic Alcohols with CO2.

A switchable site-selective catalytic carboxylation of allylic alcohols has been developed in which CO2 is used with dual roles, both facilitating C-OH cleavage and as a C1 source. This protocol is characterized by its mild reaction conditions, absence of stoichiometric amounts of organometallic reagents, broad scope, and exquisite regiodivergency which can be modulated by the type of ligand em...