Brønsted acid-catalyzed benzylation of 1,3-dicarbonyl derivatives.

The direct alkylation of 1,3-dicarbonyl compounds with benzylic alcohols is shown to be efficiently catalyzed by simple Brønsted acids such as triflic acid (TfOH) and p-toluenesulfonic acid (PTS) to give rise to monoalkylated dicarbonyl derivatives in high yields. In the absence of the nucleophile, substituted alkenes, generated through a formal dimerization reaction, are obtained. The reactions are carried out in air using undried solvents, with water being the only side product of the process.

Brønsted acid catalyzed propargylation of 1,3-dicarbonyl derivatives. Synthesis of tetrasubstituted furans.

Simple Brønsted acids such as p-toluenesulfonic acid monohydrate (PTS) efficiently catalyze a direct substitution of the hydroxyl group in propargylic alcohols with 1,3-dicarbonyl compounds. Selective propargylation or allenylation is obtained depending on the nature of the alkynol. Reactions can be performed in air in undried solvents with water being the only side product of the process.

[Li(CH(Me)P(Ph)2(NCO2Me))2(THF)2]: crystal, solution, and calculated structure of a N-delocalized lithium phosphazene.

The first crystal structure of the lithium complex of a P-alkyl-P,P-diphenyl(N-methoxycarbonyl)phosphazene has been characterized. It is dimeric, with the anion chelating the lithium in an unusual six-membered ring. A monomer-dimer equilibrium has been identified in THF solution.