Electrochemical Heterodifunctionalization of α-CF3 Alkenes to Access α-Trifluoromethyl-β-sulfonyl Tertiary Alcohols

An unprecedented electrochemical heterodifunctionalization of α-CF3 alkenes with benzenesulfonyl hydrazides was accomplished in this work, wherein a β-sulfonyl and a α-hydroxyl group were simultaneously incorporated across the olefinic double bond...

An orthorhombic polymorph of (E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(2,3-dichlorophenyl)prop-2-en-1-one

The title compound, C16H10Cl2O3, is almost planar with a dihedral angle of 0.14 (16)° between the benzodioxole ring system and the dichlorobenzene ring that are bridged by the olefinic double bond. The corresponding value reported for the monoclinic polymorph is [5.57 (9)° (Lokeshwariet al.(2017).IUCrData,2, x170103). The carbonyl group lies almost in the plane of the olefinic double bond and is twisted slightly from the benzodioxole ring plane. In the crystal, the molecules are linked by weak C—H...O and C—H...Cl hydrogen bonds, forming a chain propagating along theb-axis direction.

(E)-1-(3-Bromophenyl)-3-(3-fluorophenyl)prop-2-en-1-one

In the title compound, C15H10BrFO, the olefinic double bond adopts an E conformation. The molecule is non-planar as seen by the dihedral angle of 48.92 (11)° between the bromophenyl and fluorophenyl rings. The carbonyl group is twisted from the plane of the bromophenyl ring and the olefinic double bond. The trans conformation of the C=C double bond in the central enone group is confirmed by the C—C=C—C torsion angle of −165.7 (2)°.

(E)-1-(Benzo[d][1,3]dioxol-5-yl)-3-(2,3-dichlorophenyl)prop-2-en-1-one

In the title compound, C16H10Cl2O3, the olefinic double bond adopts anEconformation [C—C=C—C torsion angle = −172.9 (3)°]. The dihedral angle between the benzodioxole and dichlorobenzene rings is 5.57 (9)°. In the crystal, molecules are linked by weak C—H...O and C—H...Cl hydrogen bonds, forming chains propagating along thec-axis direction.

(E)-1-(1,3-Benzodioxol-5-yl)-3-[4-(dimethylamino)phenyl]prop-2-en-1-one

In the title compound, C18H17NO3, the olefinic double bond adopts anEconformation. The molecule is nearly planar as indicated by the dihedral angle of 3.11 (6)° between the benzodioxole and benzene rings. The carbonyl group lies in the plane of the olefinic double bond and the benzodioxole ring. Thetransconformation of the C=C double bond in the central enone group is confirmed by the C=C—C—C torsion angle of −177.82 (14)°.

(E)-3-(2,3-Dichlorophenyl)-1-(2-methoxyphenyl)prop-2-en-1-one

In the title compound, C16H12Cl2O2, the olefinic double bond adopts anEconfiguration. The molecule is non-planar, as shown by the dihedral angle of 15.40 (19)° between the 2,3-dichlorophenyl ring and the 2-methoxyphenyl ring. In the crystal, molecules are linkedviaweak C—H...O hydrogen bonds, forming zigzag chains propagating along thecaxis.

(E)-1-(5-Chlorothiophen-2-yl)-3-(2,4-dimethylphenyl)prop-2-en-1-one

In the title compound, C15H13ClOS, the olefinic double bond adopts anEconfiguration. The molecule is nearly planar, as seen by the dihedral angle of 9.07 (8)° between the thiophene and phenyl rings. Thetransconfiguration of the C=C double bond in the central enone group is confirmed by the C—C=C—C torsion angle of 177.6 (2)°. In the crystal, molecules are linked by weak C—H...O and C—H...S hydrogen bonds, forming chains propagating along thecaxis.

An easy approach to dihydrochalcones via chalcone in situ hydrogenation

Dihydrochalcones are polyphenols that exhibit a diversity of bioactivities, namely anti-inflammatory, antimicrobial and antiviral. We have explored the synthetic access to such molecular entities, and describe now an easy and scalable approach based on reduction of the olefinic double bond of chalcone precursors via in situ hydrogenation with the system Et3SiH-Pd/C in very high yield. The intermediate chalcones were synthesized also by a simple and efficient microwave-assisted Claisen–Schmidt condensation of aromatic aldehydes with acetophenones, conveniently protected with ethoxymethyl ether, if required. Chalcones were obtained as single reaction product in high yield in 2–3 h, while under conventional conditions at room temperature the reaction was carried out with completion only after 24 h. In addition, microwave irradiation has proven very efficient for deprotection of ethoxymethyl ether with iron chloride in only 10 min and very high yield.

Methyl (E)-3-(2-formylphenoxy)acrylate

In the title compound, C11H10O4, the methyl acrylate substituent adopts an extendedEconformation with all torsion angles close to 180°. The conformation of the keto group with respect to the olefinic double bond is typicallyS-trans. In the crystal, molecules are linkedviapairs of C—H...O hydrogen bonds, forming inversion dimers with anR22(8) graph-set motif. The dimers are further linkedviaC—H...O hydrogen bonds, forming chains along [001], which encloseR32(16) graph-set ring motifs. The keto group O atomaccepts two C—H...O interactions.