Danfeng Huang

A Powerful Reagent for Synthesis of Weinreb Amides Directly from Carboxylic Acids

A powerful reagent, P[NCH(3)(OCH(3))](3) (3), for conversion of carboxylic acids directly to Weinreb amides was developed. In most cases the yields of the corresponding Weinreb amides were above 90% when P[NCH(3)(OCH(3))](3) was heated with aromatic and aliphatic carboxylic acids in toluene. The sterically hindered carboxylic acids can also give the corresponding Weinreb amides in excellent yields.

A RAPID AND EFFICIENT SYNTHESIS OF SYMMETRICAL DISULFIDES UNDER MICROWAVE IRRADIATION CONDITIONS

ABSTRACT A rapid and general method for the synthesis of symmetrical disulfides involves reaction of sulfur with sodium hydroxide under PTC-microwave irradiation condition to give sodium disulfide, which reacts with alkyl halides to afford the disulfides in good to excellent isolated yields.

A NEW SOLVENT-FREE SYNTHESIS OF α,β-UNSATURATED KETONES FROM ACETALS WITH ARYL KETONES UNDER MICROWAVE IRRADIATION

ABSTRACT A new, rapid and efficient method for the synthesis of α,β-unsaturated ketones under microwave irradiation conditions is described. The process involves the reaction of acetals with aryl ketones in the absence of solvent using Lewis acids as catalysts under microwave irradiation to afford the α,β-unsaturated ketones in good to excellent isolated yields. The reaction mechanism is briefly discussed.

Trichloroisocyanuric Acid Promoted Cascade Cyclization/Trifluoromethylation of Allylic Oximes: Synthesis of Trifluoromethylated Isoxazolines

Cheap and commercially available trichloroisocyanuric acid has been used to promote trifluoromethylation by using TMSCF3 as the trifluoromethyl source. The method provides a novel and efficient protocol for the construction of CF3-containing 4,5-dihydroisoxazoles from allylic oximes in good to excellent yields.

A FACILE SYNTHESIS OF CONJUGATED ACETYL KETONES BY Pd(II)-Cu(I) DOPED KF/Al2O3-CATALYZED UNDER MICROWAVE IRRADIATION

A rapid and efficient method for synthesis of α,β-conjugated acetylenic ketones involves reaction ofphenylacetylene with aroyl chlorides in the presence of acatalytic amount Pd(PPh3)2Cl2-CuIdoped KF/Al2O3 under microwave irradiationto give the corresponding α,β-conjugated acetylenicketones 3a–g in 81–94% yield.

The influence of main group metallic lewis acids on the formation and reactivity of grignard reagents

The significance of main group metallic Lewis acids such as LiCl, MgCl2, AlCl3 on the formation and reactivities of Grignard reagents are best demonstrated by recent quick development of their diverse synthetic techniques and versatile reactivities towards various electrophiles. Although substantial progress has been made especially on the selective formation of carbon-metal bonds employing lithium chloride as the activator, novel protocols especially these for regioselective metalation of highly functionalized substrates are continuously developed and thus occupy a hot research spot in organometallic chemistry. This mini-review provides a concise overview mainly on the behavior of main group metallic salts derived from lithium, magnesium and aluminum as a powerful tool for regioselective metalation of C-X ( X = Cl, Br, I) and C-H bonds. The diverse functions of these metallic salts on the reactivities of Grignard reagents are exemplified primarily choosing aldehyde as the electrophile.

THE SYNTHESIS OF 1-ARYLSELENO- 3-ALKOXY-2-PROPANOLS UNDER MICROWAVE IRRADIATION CONDITIONS

ABSTRACT A simple rapid, and efficient synthetic method of 1-arylseleno-3-alkoxy-2-propanol by reducing diaryl diselenides with sodium borohydride in basic environment and their reaction with epoxypropoxyalkoxyls under microwave irradiation described.

Solid–Liquid Phase-transfer Catalytic Synthesis of Chiral Glycerol Sulfide Ethers Under Microwave Irradiation†

Epoxypropoxyphenols react with benzenethiols under phase-transfer catalysis and microwave irradiation to give chiral glycerol sulfide ethers, this procedure is simple, rapid and efficient.

(Z)-N-[(Z)-3-(2,4-Dimethyl­phenyl­imino)­butan-2-yl­idene]-2,4-dimethyl­aniline

The asymmetric unit of the title compound, C20H24N2, contains one half -molxadecule which exhibits a crystallographically imposed center of symmetry. The benzene rings are inclined to the 1,4-diazaxadbutadiene mean plane by 78.3u2005(2)°.The asymmetric unit of the title compound, C20H24N2, contains one half -molecule which exhibits a crystallographically imposed center of symmetry. The benzene rings are inclined to the 1,4-diazabutadiene mean plane by 78.3u2005(2)°.

(4RS)-Methyl 4-cyano-4-cyclo-hexyl-4-phenyl-butano-ate.

In the crystal structure of the title compound, C18H23NO2, there are only van der Waals interactions present. The cyclohexyl ring has a chair conformation. The longer axes of the displacement parameters of the non-H atoms forming the ethylmethylcarboxylate skeleton are perpendicular to the plane through the non-H atoms of this skeleton.