A catalytic approach to the metal-free reaction of epoxides with ketene silyl acetals for accessing γ-lactones.

The first catalytic approach to the nucleophilic addition of silyl ketene acetals 2 to epoxides 1 is reported. The defined protocol is metal-free using tetrabutylammonioum fluoride as the catalyst. It works in a very efficient manner under solvent-free conditions (SolFC) allowing γ-lactones 3 to be directly obtained with high regioselectivities and yields.

E-Factor minimized hydrophosphonylation of aldehydes catalyzed by polystyryl-BEMP under solvent-free conditions.

An efficient protocol for the hydrophosphonylation of aromatic and aliphatic aldehydes catalyzed by PS-BEMP under solvent-free conditions (SolFC) has been reported. Addition reactions were performed by using equimolar amounts of reagents and the resulting α-hydroxyphosphonates were isolated with simple workup procedures. A large scale protocol for the preparation of a representative α-hydroxyphosphonate 3a has been also set up using a flow reactor.

A protocol for accessing the β-azidation of α,β-unsaturated carboxylic acids.

This contribution reports the preparation and use of a new immobilized catalyst, PS-DABCOF (9), which has been specifically designed to access for the first time the efficient β-azidation of α,β-unsaturated carboxylic acids.

Sc(III)-catalyzed enantioselective addition of thiols to α,β-unsaturated ketones in neutral water.

This report concerns Lewis acid catalyzed enantioselective sulfa-Michael addition in neutral water by using a very efficient Sc(OTf)(3)/bipyridine 1 catalytic system. It is noteworthy that the protocol presented employs water as a reaction medium and allows us to obtain very high stereoselectivity and satisfactory yields for β-keto sulphides deriving from aliphatic thiols. The recovery and reuse of both the aqueous medium and the catalytic system is also reported.