A facile route towards highly functionalized 3(2H)-furanones via a sequential Mannich addition-palladium catalyzed ring closing has been elaborated. The reaction of 4-chloroacetoacetate esters with imines derived from aliphatic and aromatic aldehydes under palladium catalysis afforded 4-substituted furanones in good to excellent yields. 4-Hydrazino-3(2H)-furanones could also be synthesized from...

An additive-free Pd-catalyzed α-allylation of different imino-group-ontaining heterocycles is reported. The activation of α-CH pronucleophiles (pKa (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic in...

The complex formed from Pd(CH(3)CN)(4)(BF(4))(2) and (R,R)-MeDUPHOS is a highly enantioselective catalyst for the asymmetric conjugate addition of aryltriethylsiloxanes to a variety of unsaturated ketones, lactones and lactams.

The copper-catalyzed conjugate addition-cycloacylation reaction of zinc homoenolatee with acetylenic esters or acetylenic amides is described. The zinc homoenolate is prepared from [ (ethoxycyclopropy1)oxyltrimethylsilane and zinc chloride in ether. Addition of an acetylenic amide or ester provides 2-carboxamidoor 2-carboalkoxy-3-alkylcyclopent-2-en-l-ones ingood to excellent yields. The reacti...

A fluorescent chemodosimeter for cysteine detection was developed based on a tandem conjugate addition and intramolecular cyclization reaction. The method exhibited an excellent selectivity for cysteine over other biothiols such as homocysteine and glutathione.

Herein we have elucidated unusual and unique nucleophilic conjugate 1,3-addition reactions of surveyed oligoynoates toward phosphines through spectroscopic and single crystal X-ray diffraction analyses of three-component reaction products of oligoynoates, phosphines and aldehydes.