Synthesis and antifungal activity of new salicylic acid derivatives

A simple one-step procedure for synthesis of 1-methoxy-1-oxoalkan-2-yl salicylates and 1-methoxy-1-oxoalkan-2-yl 2-[(1-methoxy-1-oxoalkan-2-yl)oxy]benzoates by reaction of salicylic acid with several methyl 2-bromoalkanoates was developed. The reactions were carried out in N,N-dimethylformamide (DMF) in the presence of anhydrous potassium carbonate. Conditions for regioselective synthesis of target compounds were established. The developed procedure could be easily applied in the industrial production process. The new salicylic acid derivatives were obtained with satisfactory yields and were characterized by MS and 1H NMR spectra. The fungicidal activity of the prepared compounds was tested in vitro against seven species of plant pathogenic fungi. The best results were observed for 1-methoxy-1-oxoalkan-2-yl salicylates which showed moderate or good activity against Botrytis cinerea and Rhizoctonia solani.

Photoresponsive polymer brushes for hydrophilic patterning

The use of photolabile protecting groups (PGs) as a means to create latent hydrophilic surfaces is presented. Naturally hydrophobic PGs, based on o-nitrobenzyl chemistry, are used on polymer side chains, poised for cleavage upon exposure to UV light. Removal of the PGs liberates the hydrophilic polymer, thereby switching the surface wettability from hydrophobic to hydrophilic. This switch can be augmented by increasing the surface roughness. Additionally, this system is also shown to be spatially addressable, a highly desirable property for applications which require specific regions of a surface to switch their wettability.

Metal-dependent reactions of bulky metal(II) amides M[N(SiMe3)2]2 with 3,3'-disubstituted binaphthols (HO)2C20H10(SiR3)2-3,3': selective conversion of one equivalent -OH group to a silyl ether -OSiMe3

The outcome of the reaction of the bulky metal(II) amides M[N(SiMe3)2]2. nTHF (M = Be, Zn, Ge, Sn, n = 0; M = Mg, Ca, n = 2) with (R)-3,3'-bis(trimethylsilyl)-1,1'-bi-2,2'-naphthol ((R)-1) or (S)-3,3'-bis(dimethylphenylsilyl)-1,1'-bi-2,2'-naphthol ((S)-9) depends on the identity of the metal and the nature of the 3,3'-substituents. When M = Be, Zn, or Ge, these amides serve as useful silylation agents that convert only one of the equivalent hydroxyl groups of the binaphthol (R)-1 to a trimethylsilyl ether, whereas the reactions of (R)-1 with the Mg, Ca, or Sn amides generate a polynuclear complex. The reaction pathway for these interconversions was qualitatively monitored using NMR ((1)H and (9)Be) spectroscopy. Treatment of Ge[N(SiMe3)2] 2 with (S)-9 yields both a silyl ether and the chelated germanium(II) binaphthoxide (S)-[Ge{O2C20H10(SiMe2Ph)2-3,3'}{NH3}], which was structurally characterized.