The Synthesis of Novel Oxazolinylphosphinic Esters and Amides and Application to the Cyanosilylation of Aldehydes

Author(s):

Mei LuoPages 660-672 (13)

Abstract:

A new class of modular functionalized oxazolines are synthesized using a simple, novel one-pot method under inert moisture-free conditions. Then the oxazolines can be further elaborated to phosphine-containing oxazolines. The first step is to synthesize intermediates via the reaction of 2 - hydroxybenzonitrile or 2- aminobenzonitrile with chiral amino alcohols, subsequent reactions with phosphine chlorides, providing products in moderate yields. Product structures are fully characterized by NMR, IR, MS and X-Ray analyses. These compounds are found to be highly active catalysts for the cyanosilylation of prochiral benzaldehyde (20-96% yield).

Keywords:

Functionalized oxazolines, chiral organometallic complexes, 2-hydroxybenzonitrile, 2- aminobenzonitrile, chiral amino alcohols, phosphine chlorides.

Affiliation:

Hefei University of Technology, Department of Chemical Engineering, Hefei, 230009, China.

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New Imidazolidineiminothione, Imidazolidin-2-one and Imidazoquinoxaline Derivatives: Synthesis and Evaluation of Antibacterial and Antifungal Activities

Author(s):

Yousry A. Ammar, Marwa A. M. Sh. El-Sharief, Mostafa M. Ghorab, Yehia A. Mohamed, Ahmed Ragab and Samir Y. AbbasPages 466-475 (10)

Abstract:

A series of new 5-imino-4-thioxo-2-imidazolidinone derivatives 3 with various halogenated and alkylated aromatic substituents at N1and N3 was synthesized. Imidazolidineiminothione derivatives 3 were prepared from the reaction of N-arylcyanothioformamide derivatives with aryl isocyanates. These compounds were used as key synthons for the preparation of wide variety of new substituted imidazole compounds. Imine hydrolysis of 3 with ethanolic HCl produced the corresponding 4-thioxo-2,5-imidazolidindiones 4. Condensation of 3 with benzophenonhydrazone furnished the corresponding 4-azine derivatives 5. Monohydrazono and dihydrazono derivatives 6 and 8 were obtained upon treatment of imidazolidinone derivatives 3 with hydrazine hydrate. Finally, imidazolidinones 3 were reacted with o-phenylenediamines or pyrazol- 5(4H)-ones and afforded the corresponding imidazoquinoxaline and imidazolidin-4-ylidenepyrazolone-5(4H)-one derivatives 11 and 12, respectively. Evaluation of the antibacterial and antifungal activities for the synthesized compounds was carried out to probe their activities. Most of the tested compounds showed significant activities. The best antimicrobial activity was observed for 1-(3-ethoxyphenyl)-6- methyl-1-phenyl-1H-imidazo[4,5-b]quinoxalin-2(3H)-ones (11c) followed by 5-imino-3-(3-methoxy- phenyl)-1-phenyl-4- thioxoimidazolidin-2-one (3f).

Keywords:

N-arylcyanothioformanilides, imidazolidineiminothiones, imidazolidinone, imidazoquinoxaline, antibacterial and antifungal activities.

Affiliation:

Pharmacognosy Department, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

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The Cyanation of Prochiral Aldehydes with Chiral Copper Complexes of R-(+)/S-(-) -α -Ethylphenyl Amine in Methanol

Author(s):

Luo MeiPages 476-482 (7)

Abstract:

Interesting and unexpected results on the cyanation of prochiral aldehydes catalyzed by chiral copper complexes of R-(+)/(S)-(-) α -ethylphenyl amine (I/II) in anhydrous methanol are presented. The cyanation reaction with chiral copper complexes of R-(+)/S-(-) α -ethylphenyl amines, acetols in methanol perform to afford a series of chiral products such as amines and acetonitriles (compounds 4-6, 8, 10 and 11). The obtained products are fully characterized by NMR, IR and X-ray analysis. The proposed mechanism for the formation of a series of chiral products can be concluded that methanol firstly promotes the decomposition of the copper complexes bearing R- (+)/S-(-) α -ethylphenyl amines to the ligand R-(+)/ S-(-)- α-ethylphenyl amine, which then conjugated with the initial TMS ether of the cyanohydrin or cyanohydrin to afford the chiral compounds 4-6, 8, 10 and 11.

Keywords:

Cyanation, chiral copper complexes, R-(+)/S-(-) - α-ethylphenyl amine, methanol, acetols, cyanohydrin.

Affiliation:

Hefei University of Technology, Department of Chemical Engineering, Hefei, 230009, China.

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