Ruthenium-catalyzed regioselective synthesis of 2-substituted indoles via ring-opening of epoxides by anilines

Anilines react with epoxides in dioxane at 180°C in the presence of a catalytic amount of a ruthenium catalyst along with tin(II) chloride to afford 2-substituted indoles in moderate to good yields.     

Novel applications of 2-cyanoethylanilines in the synthesis of conjugated primary and secondary anilines

2-Cyanoethyl anilines were controllably cleaved by 1 equiv of potassium t-butoxide in dry THF with a reaction that can be used in situ with the Wittig reaction to synthesize conjugated primary and secondary anilines.     

Darstellung und Strukturen einiger N-(Tri-t-butoxysilyl)anilin-Derivate

Formation and Structures of N-(tri-t-butoxysilyl)aniline Compounds Para-substituted N-(tri-t-butoxysilyl)anilines (t-BuO)₃SiNRC₄H₄X-p, R = H, CH₃, with substituents of high electron affinity (X = CN, NO₂) were prepared by a one-pot reaction of tri-t-butoxychlorsilane, potassium t-butanolate and substituted anilines. Corresponding compounds with substituents of low electron affinity (X = OMe, H) preferably were prepared by metalation of anilines with sodium amide. Four crystal structures were determined. N-(tri-t-butoxysilyl)-p-nitro-aniline, N-methyl-(N-tri-t-butoxysilyl)-p-nitroaniline and N-(tri-t-butoxysilyl)-p-cyanoaniline crystallize at 298 K monoclinically, N-(tri-t-butoxysilyl)aniline crystallizes orthorhombically.     

Reaction of the carbonate radical with substituted anilines

Rate constants for the reaction of carbonate radical with aniline and some parasubstituted anilines have been determined by the flash photolysis technique. Using σ⁺ para values the rate constants at pH 8.5 correlate very well with the Hammett equation yielding ρ= − 1. The carbonate radical oxidises aniline giving the anilino radical. The products so formed have been identified through studies under conditions of continuous irradiation.     

Activation thermodynamic parameters of binary mixtures of propionic acid ando-substituted anilines

Variations of densities and viscosities with temperature and composition are reported for binary liquid mixtures containing propionic acid+aniline (I),+o-toluidine (II),+o-anisidine (III), and+o-chloroaniline (IV). Entropies S _m and enthalpies H _m of activation as functions of the composition of the mixtures, as well as free energies of activation G _m at 10, 20, 30, 40, and 50°C and different compositions were calculated by means of Eyring's equation. The formation of activated complexes between the components of these binary mixtures is postulated and claimed to result from acid-base and hydrogen bonding exchange interactions.     

A facile method for the synthesis of 3,1-benzooxazines from N-acyl-2-(alk-2-enyl)anilines

Electrophilic addition of HCl or Br₂ to N-acyl-2-(alk-2-enyl)anilines is accompanied by intramolecular cyclization of these amides to give 3,1-benzooxazine hydrochlorides or hydrobromides in high yields.     

1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane: a new application for catalyzing the direct substitution of 9H‐xanthen‐9‐ol at room temperature

1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane was firstly used to catalyze the direct substitution of 9H‐xanthen‐9‐ol with indoles at room temperature to afford a class of 3‐(9H‐xanthen‐9‐yl)‐1H‐indole derivatives in good to excellent isolating yield. Moreover, other nucleophiles (such as diketone and pyrrole) could also proceed smoothly in this methodology. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of (22R, 25R)-3β,26-Dihydroxy-5α-furostan-6-one #

The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described.

     

Aminomethyl Transfer (Mannich) Reactions Between an O-Triethylsilylated Hemiaminal and Anilines,RnC6H5−nNH2 Leading to New Diamines,Triamines, Imines,or 1,3,5-Triazines Dependent upon Substituent R

The reactions of the Mannich reagent Et₃SiOCH₂NMe₂ ( 1 ) with a variety of anilines (mono-substituted RC₆H₄NH₂, R=H, 4-CN, 4-NO₂, 4-Ph, 4-Me, 4-MeO, 4-Me₂N; di-substituted R₂C₆H₃NH₂, R₂=3,5-(CH₃)₂, 3,5-(CF₃)₂; tri-substituted R₃C₆H₂NH₂, R₃=3,5-Me₂-4-Br and a “super bulky” aniline (Ar*NH₂) [Ar*=2,6-bis(diphenylmethyl)-4-tert-butylphenyl]) led to the formation of a range of products dependent upon the substituent. With electron-withdrawing substituents, previously unknown diamines, RC₆H₄NH(CH₂NMe₂) [R=CN ( 2 a ), NO₂ ( 2 b )] and R₂C₆H₃NH(CH₂NMe₂) [R₂=3,5-(CF₃)₂ ( 2 c) ] were formed. Further reaction of 2 a , b , c with 1 yielded the corresponding triamines RC₆H₄N(CH₂NMe₂)₂ (R=CN ( 3 a ), NO₂ ( 3 b ) and R₂C₆H₃N(CH₂NMe₂)₂, R₂=3,5-(CF₃)₂ ( 3 c ). The new polyamines were characterized by NMR spectroscopy, and for 2 a , 2 c _, and 3 c , by single crystal XRD. In the case of electron-donating groups, R=4-OMe, 4-NMe₂, 4-Me, 3,5-Me₂, 3,5-Me₂-4-Br, and for R=4-Ph, the reactions with 1 immediately led to the formation of the related 1,3,5-triazines, R=4-MeO ( 5 a ), 4-Me₂N ( 5 b ), 4-Me ( 5 c ), 3,5-Me₂ ( 5 d ), 3,5-Me₂-4-Br ( 5 e ), 4-Ph ( 5 f ), 4-Cl ( 5 g ). The “super bulky” aniline rapidly produced a single product, namely the corresponding imine Ar*N=CH₂ ( 4 ) which was also characterized by single crystal XRD. Imine 4 is both thermally and oxidatively stable. All reactions are very fast, thus based upon the presence of Si we are tempted to denote the reactions of 1 as examples of “Silick” chemistry.