105262-70-2Relevant articles and documents
Synthesis and structural characterization of two nostoclide analogues
Teixeira,Barbosa,Santana,Veloso,Ellena,Doriguetto,Drew,Ismail
, p. 197 - 205 (2007)
The vinylogous aldol reaction between appropriate aldehydes and furan-based silyloxy diene synthon generated from 3-benzyl-5H-furan-2-one (3) afforded two truncated lactone analogues [compounds (4) and (5)] of nostoclides (2). The compounds were fully cha
Spectroscopic and dynamic NMR study, X-ray crystallography and DFT calculations of two phosphoramidates: (C4H3O 2)P(O)(Cl)C6H14N and (C4H 3O2)P(O)(C6H11NH)2
Oliveira,Barbosa,Demuner,Maltha,Fernandes,Carneiro,Corrêa,Doriguetto
, p. 64 - 73 (2013/07/25)
In recent years, research in organophosphorus compounds, particularly phosphoramidates, has attracted attention because of their many applications. In this work, we report a combined experimental and theoretical study on the molecular structure and NMR spectra of two phosphoramidates (furan-2-yl N,N-diisopropylamidochlorophosphate (1) and furan-2-yl N,N,N′,N′- dicyclohexylamidophosphate (2)). In the NMR time scale a free rotation of the CN/PN single bonds was observed at room temperature (298 K) while the rotation freezes below 195 K for compound 1. From dynamic NMR analysis, the activation free energy (ΔG#) for rotation of the CN/PN bonds was calculated as 9.9 ± 0.3 kcal mol-1. The experimental data were reinforced by theoretical calculation using the density functional theory method B3LYP and the 6-31G(d) basis set which provided activation energy (ΔE?) of 9.2 kcal mol-1. The structures of compounds 1 and 2 were determined by single crystal X-ray diffraction method. Compound 1 is formed by a racemic mixture, whose presence was evidenced only in the structure determination by X-ray.
Tailoring nostoclide structure to target the chloroplastic electron transport chain
Barbosa, Luiz C. A.,Varejao, Jodieh O. S.,Petrollino, Davide,Pinheiro, Patricia F.,Demuner, Antonio J.,Maltha, Celia R. A.,Forlani, Giuseppe
scheme or table, p. 15 - 32 (2012/03/10)
Aiming to improve their effectiveness, three modifications were introduced into the structure of the natural phytotoxins nostoclides, leading to the synthesis of novel 3-benzyl-4-isopropyl-5- (arylmethylene)furan-2(5H)-ones, 3-benzyl-5-(furan-2-ylmethylene)furan-2(5H)-ones, and 3,4 dihalo-5- arylidenefuran-2(5H)-ones. All compounds were characterized by IR, 1H and 13C NMR, NOEDIF, COSY, HETCOR and MS spectrometry. Increasing the length of the molecule was found to reduce the ability to interfere with ferricyanide reduction by isolated chloroplasts. The addition of an isopropyl moiety into the heterocyclic ring, as in naturally-occurring nostoclides, did not influence the inhibitory potential. Also the replacement of the electron-drawing phenyl substituent with two halogen residues did not improve the resulting activity. However, both latter modifications influenced the interaction with the photosynthetic machinery. These analogues could therefore represent novel leads to be explored toward the development of new herbicides targeting the chloroplastic electron transport chain. ARKAT-USA, Inc.
Synthesis, structural characterization and conformational aspects of nostoclide analogues
Teixeira,Barbosa,Carneiro, J.W.de M.,Corrêa,Ellena,Doriguetto
scheme or table, p. 1 - 9 (2009/03/12)
The synthesis and structural analysis of a set of nostoclide analogues with potential herbicide activity is described. The influence of intra- and intermolecular hydrogen bonding, as well as other interactions on the conformation and packing of the compounds is thoroughly described using DFT calculations and single crystal X-ray diffraction analyses. All lactones exhibited the Z configuration as confirmed by NOESY experiments and by single crystal X-ray diffraction measurements.
Phytogrowth activity of 3-(3-Chlorobenzyl)-5-arylidenefuran-2(5H)-ones
Barbosa, Luiz C. A.,Demuner, Antonio J.,Maltha, Celia R. A.,Teixeira, Robson R.,Souza, Kamilla A. P.,Bicalho, Keylla U.
scheme or table, p. 245 - 251 (2009/06/17)
Nine new 3-(3-chlorobenzyl)-5-arylidenefuran-2(5H)-ones were prepared in 20-87% yields by reaction of 3-(3-chlorobenzyl)furan-2(5H)-one with pertinent aldehydes. All compounds were fully characterized by IR and NMR spectroscopy as well as MS spectrometry. The phytotoxic properties of the synthesized lactones were evaluated as the ability to interfere with the growth of Sorghum bicolor and Cucumis sativus seedlings at 10 ppm and 100 ppm. Lactone 12, at 10 ppm, was the most active and selective, inhibiting the S. bicolor and C. sativus root growth by 70.7 % and 10.7 %, respectively. At 10 ppm, lactone 14 caused the larger effect on the inhibition (41.9 %) of C. sativus. In general, the results indicate the influence of the benzylidene ring substitution on the phytotoxic activity.
Synthesis of 3-(4-bromobenzyl)-5-(aryl methylene)-5H-furan-2-ones and their activity as inhibitors of the photosynthetic electron transport chain
Barbosa, Luiz C. A.,Rocha, Marcelo E.,Teixeira, Robson R.,Maltha, Celia R.A.,Forlani, Giuseppe
experimental part, p. 8562 - 8569 (2009/09/28)
A series of 12 3-(4-bromobenzyl)-5-(arylmethylene)-5H-furan-2-one lactones, designed using the naturally occurring toxin nostoclides as a lead structure, were synthesized and screened as potential inhibitors of photosynthetic electron transport. The structures were confirmed by 1H and 13C NMR, MS, and IR analyses. Their biological activity was evaluated both in vitro, as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts, and in vivo, as the capability to inhibite the oxygen production by intact Chlorella cells. Some of the compounds exhibited inhibitory properties in the micromolar range against basal and phosphorylating electron flow from water to K3[Fe(CN)6], with no effect on uncoupled electron flow. Thus, they seem to behave as energy-transfer inhibitors. Although poor solubility in water may limit their effectiveness, the active derivatives could present structures to be exploited for the design of new substances endowed with herbicidal activity.
TETRAMETHYLDIAMIDO PHOSPHATE DIRECTED β-LITHIATION OF A ?-EXCESSIVE HETEROCYCLE; d2-SYNTHON TO 2-SUBSTITUTED BUTENOLIDES
Naesman, Jan H.,Kopola, Nina,Pensar, Goeran
, p. 1391 - 1394 (2007/10/02)
The tetramethyldiamido phosphate group is described as a novel and tetracoordinated directing group in a reliable and synthetically useful β-lithiation of furan 1.Addition of 1.1 equiv. n-BuLi to 1 and quenching with electrophiles gave 2,3-disubstituted furans 3.In 98-100 percent formic acid 3 is converted to 4 in good overall yield.Thus furyltetramethyldiamido phosphate 1 is a d2-synthon for 2-furanone.
