0000000000515779
AUTHOR
Laura Carceller-ferrer
Catalytic Diastereo- and enantioselective vinylogous Mannich reaction of alkylidenepyrazolones to isatin-derived ketimines
A valuable organocatalytic vinylogous Mannich reaction between alkylidenepyrazolones and isatin-derived ketimines has been successfully established. Squaramide organocatalyst, prepared from quinine, catalyzed the diastereo- and enantioselective vinylogous Mannich addition, affording a range of aminooxindole-pyrazolone adducts (24 examples) with excellent outcomes: up to 98% yield with complete diastereoselectivity and excellent enantioselectivity (up to 99% ee). Additionally, different synthetic transformations were performed with the chiral pyrazolone-oxindole adducts.
Catalytic Diastereo- and Enantioselective Synthesis of Tertiary Trifluoromethyl Carbinols through a Vinylogous Aldol Reaction of Alkylidenepyrazolones with Trifluoromethyl Ketones
A diastereo- and enantioselective organocatalytic aldol reaction between alkylidenepyrazolones and trifluoromethyl ketones leading to chiral tertiary alcohols bearing a trifluoromethyl group is presented. The methodology is based on the use of a bifunctional organocatalyst in order to activate the γ-hydrogen atoms of the alkylidenepyrazolone nucleophile and the carbonyl group of the trifluoromethylarylketone providing highly functionalized trifluoromethyl alcohols with moderate yields, excellent diastereoselectivity, and moderate to good enantioselectivity. Experiments monitoring the conversion by 1H NMR and the enantiomeric excess by HPLC with the reaction time showed that full conversion …
Organocatalytic Enantioselective Aminoalkylation of 5‐Aminopyrazole Derivatives with Cyclic Imines
The first enantioselective alkylation of 5‐aminopyrazoles is described with good results. The organocatalytic alkylation of 5‐aminopyrazoles have been accomplished using benzoxathiazine 2,2‐dioxides as electrophiles and a bifunctional squaramide organocatalyst.
Organocatalytic enantioselective aminoalkylation of pyrazol-3-ones with aldimines generated in situ from α-amido sulfones
Herein, an efficient asymmetric aminoalkylation of pyrazolones with α-amido sulfones catalyzed by a quinine-derived squaramide in dichloromethane/aqueous media has been established. A variety of chiral amines were obtained with high yields (up to 98%) and excellent enantioselectivities (up to 99% ee). The corresponding products are transformed into optically active acetylated pyrazoles after treatment with Ac2O/Et3N, because of the instability of some adducts. The reaction tolerates a wide range of α-amido sulfones and different pyrazolones.
Recent Advances in Catalytic Enantioselective Synthesis of Pyrazolones with a Tetrasubstituted Stereogenic Center at the 4-Position
AbstractPyrazolone [2,4-dihydro-3H-pyrazol-4-one] represents one of the most important five-membered nitrogen heterocycles which is present in numerous pharmaceutical drugs and molecules with biological activity. Recently, many catalytic methodologies for the asymmetric synthesis of chiral pyrazolones have been established with great success, specially, for the synthesis of pyrazolones bearing a tetrasubstituted stereocenter at C-4. This review summarizes these excellent research studies since 2018, including representative examples and some mechanistic pathways explaining the observed stereochemistry.1 Introduction2 Catalytic Enantioselective Synthesis of Chiral Pyrazolones with a Full Car…
Squaramide-Catalyzed Enantioselective Michael Addition of Pyrazol-3- ones to ortho-Quinone Methides
A bifunctional squaramide catalyzed the enantioselective Michael addition of pyrazol-3- ones to ortho-quinone methides, generated in situ from 2-(1-tosylalkyl)phenols is presented. The corresponding chiral pyrazolones are obtained with good to excellent yields (27-98%) and enantiomeric excess (14-99% ee).
CCDC 1944351: Experimental Crystal Structure Determination
Related Article: Laura Carceller-Ferrer, Carlos Vila, Gonzalo Blay, Isabel Fernández, M. Carmen Muñoz, José R. Pedro|2019|Org.Biomol.Chem.|17|9859|doi:10.1039/C9OB02252J
CCDC 2122953: Experimental Crystal Structure Determination
Related Article: Laura Carceller-Ferrer, Aleix González del Campo, Carlos Vila, Gonzalo Blay, M. Carmen Muñoz, José R. Pedro|2022|J.Org.Chem.|87|4538|doi:10.1021/acs.joc.1c02817
CCDC 2092891: Experimental Crystal Structure Determination
Related Article: Laura Carceller-Ferrer, Carlos Vila, Gonzalo Blay, M. Carmen Muñoz, José R. Pedro|2021|Org.Lett.|23|7391|doi:10.1021/acs.orglett.1c02571
CCDC 2024661: Experimental Crystal Structure Determination
Related Article: Laura Carceller-Ferrer, Aleix González del Campo, Carlos Vila, Gonzalo Blay, M. Carmen Muñoz, José R. Pedro|2020|Eur.J.Org.Chem.|2020|7450|doi:10.1002/ejoc.202001314
CCDC 2092892: Experimental Crystal Structure Determination
Related Article: Laura Carceller-Ferrer, Carlos Vila, Gonzalo Blay, M. Carmen Muñoz, José R. Pedro|2021|Org.Lett.|23|7391|doi:10.1021/acs.orglett.1c02571