application of allylic sulphoxides and, particularly, the chiralamine reagent tert-butanesulphinamide has been extended to three different tandem processes. The condensation of (R)-(+)-allyl p-tolyl sulphoxide, fluorinated nitriles and alkyl propiolates led to a new family of enantiomerically pure fluorine-containing 1,4- dihydropyridines. A diastereoselective nucleophilic addition of fluorinated nucleophiles
A new strategy for the synthesis of fluorinated 3,4-dihydropyrimidinones
作者:Santos Fustero、Silvia Catalán、José Luis Aceña、Carlos del Pozo
DOI:10.1016/j.jfluchem.2009.06.001
日期:2009.12
A new family of 3,4-dihydropyrimidinones (DHPMs) bearing fluorinated substituents at C6 have been prepared from gem-difluorinated nitriles, alkyl 3-butenoates and iso(thio)cyanates. This novel Biginelli-type process relies on the γ-addition of the ester-derived enolate to fluorinatednitriles. A tandem nucleophilic addition aza-Michael reaction sequence completes the synthetic process.
Microwave-Assisted Tandem Cross Metathesis Intramolecular Aza-Michael Reaction: An Easy Entry to Cyclic β-Amino Carbonyl Derivatives
作者:Santos Fustero、Diego Jiménez、María Sánchez-Roselló、Carlos del Pozo
DOI:10.1021/ja0709829
日期:2007.5.1
Hoveyda-Grubbs catalyst in combination with BF3 center dot OEt2 efficiently promotes tandem cross metathesis intramolecular aza-Michael reaction between enones and unsaturated carbamates resulting in the creation of beta-amino carbonyl units. The use of microwave irradiation dramatically accelerates the process, enhancing the synthetic utility of this methodology for the preparation of these types of derivatives. When enantiomerically enriched alpha-branched amines were used as starting materials, the process was also very efficient, although with modest selectivity in the newly created stereocenter. The use of microwave irradiation led to an interesting effect, inverting the selectivity in the addition process.
Tandem Asymmetric Michael Reaction−Intramolecular Michael Addition. An Easy Entry to Chiral Fluorinated 1,4-Dihydropyridines
作者:Santos Fustero、Silvia Catalán、María Sánchez-Roselló、Antonio Simón-Fuentes、Carlos del Pozo
DOI:10.1021/ol101318t
日期:2010.8.6
A novel one-pot tandem asymmetric Hantzsch-type process has been employed to generate fluorinated 1,4-dihydropyridines (1,4-DHPs) as single diastereoisomers. It involves the condensation of (R)-(+)-allyl p-tolyl sulfoxide, fluorinated nitriles, and alkyl propiolates, giving access to a new family of enantiomerically pure fluorine-containing 1,4-DHPs.