•Novel in situ copper(I) iodide schiff base catalysts.•High activity for the aerobic oxidation of benzylic, allylic and aliphatic alcohols.•Quantitative yields for benzaldehyde in 3 h with a catalyst ...loading of 2.5 mol%.•Diol oxidation to the corresponding lactol.
We report here novel Cu(I) thiophene carbaldimine catalysts for the selective aerobic oxidation of primary alcohols to their corresponding aldehydes and various diols to lactones or lactols. In the presence of the in situ generated Cu(I) species, a persistent radical (2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO)) and N-methylimidazole (NMI) as an auxiliary ligand, the reaction proceeds under aerobic conditions and at ambient temperature. Especially the catalytic system of 1-(thiophen-2-yl)-N-(4-(trifluoromethoxy)phenyl)methanimine (ligand L2) with copper(I)-iodide showed high reactivity for all kind of alcohols (benzylic, allylic and aliphatic). In the case of benzyl alcohol even 2.5 mol% of copper loading gave quantitative yield. Beside high activity under aerobic conditions, the catalysts ability to oxidize 1,5-pentadiol to the corresponding lactol (86% in 4 h) and N-phenyldiethanolamine to the corresponding morpholine derivate lactol (86% in 24 h) is particularly noteworthy.
Display omitted
The present investigation focuses on analysis of swelling behavior of systems composed of linear primary alcohols and photo-chemically crosslinked poly (butyl prop-2-enoate) (PABu). For this purpose, ...reactive blends composed of monofunctional (n-ABu) and difunctional (1-prop-2-enoyloxyhexyl prop-2-enoate) monomers as well as a standard photoinitiator were exposed to ultraviolet-visible (UV–vis) irradiation to induce free radical crosslinking polymerization. Experimental swelling studies of the obtained optically transparent PABu networks in methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol and heptan-1-ol were performed by gravimetric sorption measurements. Among the various models available to rationalize the swelling kinetics of these PABu-alcohol systems, the second order approach was found to agree well with the experimental data.
In particular it was observed that swelling properties strongly depend on the length of the linear alkyl chain of the primary alcohols. Swelling of PABu network at equilibrium increases from methanol to butan-1-ol where it reaches a maximum and subsequently decreases from butan-1-ol to heptan-1-ol. To understand this unusual behavior, polymer-solvent solubility parameters were considered, which could not account for the swelling maximum detected in the case of butan-1-ol. Molecular simulations performed on model systems composed of a linear primary alcohol molecule set and a reproduced PABu network revealed that their mutual interaction energy times the molar mass of the alcohol show a trend very similar to that of the observed swelling behavior.
Display omitted
•Swelling analysis of crosslinked poly(n-butylacrylate) by linear primary alcohols•Experimental data were successfully described by second-order kinetics.•Strong dependence of the swelling properties on the alkyl chain length•Development of model systems taking into account mutual interactions•Molecular simulations successfully explain experimental swelling data.
Foliar epicuticular waxes of specimens of 13 Croton species native in Brazil were extracted. The fractions containing alkanes and primary alcohols were isolated by preparative thin layer ...chromatography. Derivatized n-primary alcohols were identified by gas chromatography (GC) coupled with mass spectrometry and n-alkanes by GC and comparison with known standards. Relative abundances were estimated by GC coupled with flame ionization detector. The distribution of constituents of both classes was analyzed by cluster analysis, using the UPGMA method and Euclidean distances. The chemical affinities among species were compared with published data of molecular phylogenetic relationships. The distribution of n-alkanes and primary alcohols were shown to be useful markers of Croton species. Primary alcohols were more consistent than n-alkanes for species fingerprinting.
Display omitted
•Affinities based on cuticular wax constituents have no phylogenetic basis in Croton.•n-Alkanes and n-primary alcohols may be useful for characterization of Croton species.•n-Primary alcohols are more consistent then n-alkanes for Croton species characterization.
A photosensitizing covalent metal–organic framework (CMOF) was prepared as a tandem reaction catalyst by Guo‐Hong Ning, Dan Li, and co‐workers in their Research Article (e202306497). By combining ...Cu‐CTUs as metal‐catalytic sites and Bodipy linkers as photosensitizers, this CMOF can catalyze terminal alkenes and alkynes to produce primary alcohols via one‐pot tandem reactions with excellent regioselectivity, good overall yields for two‐step reactions, broad substrate compatibility and good reusability under mild conditions.
Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and ...efficacy of 26 compounds belonging to chemical group 3 (α,β‐unsaturated straight‐chain and branched‐chain aliphatic primary alcohols, aldehydes, acids and esters). They are all currently authorised as flavours in food. The FEEDAP Panel was unable to perform the assessment of non‐2(cis)‐en‐1‐ol 02.112 in the absence of data on its purity. The FEEDAP Panel concludes that hex‐2‐en‐1‐ol 02.020, pent‐2‐en‐1‐ol 02.050, 2‐dodecenal 05.037, nona‐2,4‐dienal 05.071, trans‐2‐nonenal 05.072, hex‐2(trans)‐enal 05.073, 2,4‐decadienal 05.081, hepta‐2,4‐dienal 05.084, deca‐2(trans),4(trans)‐dienal 05.140, dodec‐2(trans)‐enal 05.144, hept‐2(trans)‐enal 05.150, non‐2‐enal 05.171, undec‐2(trans)‐enal 05.184, trans‐2‐octenal 05.190, trans‐2‐decenal 05.191, tr‐2, tr‐4‐nonadienal 05.194, tr‐2, tr‐4‐undecadienal 05.196, hex‐2(trans)‐enyl acetate 09.394 and hex‐2‐enyl butyrate 09.396 are safe at the proposed maximum use level of 5 mg/kg feed for all animal species; nona‐2,6‐dien‐1‐ol 02.049, trans‐2, cis‐6‐nonadien‐1‐ol 02.231, nona‐2(trans),6(cis)‐dienal 05.058, nona‐2(trans),6(trans)‐dienal 05.172, allyl heptanoate 09.097 and allyl hexanoate 09.244 are safe at the proposed normal use levels of 1 mg/kg complete feed for all animal species. No safety concern would arise for the consumer from the use of these compounds up to the highest safe levels in feed. In the absence of studies to assess the safety for the user, the FEEDAP Panel cannot conclude on the safety for the users when handling the additives. No environmental risk is foreseen for these compounds at the concentrations considered safe for the target species. Since the 25 compounds are used in food as flavourings and their function is essentially the same as that in food, no further demonstration of efficacy is necessary.
Summary
Glaucousness is described as the scattering effect of visible light from wax deposited on the cuticle of plant aerial organs. In wheat, two dominant genes lead to non‐glaucous phenotypes: ...Inhibitor of wax 1 (Iw1) and Iw2. The molecular mechanisms and the exact extent (beyond visual assessment) by which these genes affect the composition and quantity of cuticular wax is unclear. To describe the Iw1 locus we used a genetic approach with detailed biochemical characterization of wax compounds. Using synteny and a large number of F2 gametes, Iw1 was fine‐mapped to a sub‐cM genetic interval on wheat chromosome arm 2BS, which includes a single collinear gene from the corresponding Brachypodium and rice physical maps. The major components of flag leaf and peduncle cuticular waxes included primary alcohols, β‐diketones and n‐alkanes. Small amounts of C19–C27 alkyl and methylalkylresorcinols that have not previously been described in wheat waxes were identified. Using six pairs of BC2F3 near‐isogenic lines, we show that Iw1 inhibits the formation of β‐ and hydroxy‐β‐diketones in the peduncle and flag leaf blade cuticles. This inhibitory effect is independent of genetic background or tissue, and is accompanied by minor but consistent increases in n‐alkanes and C24 primary alcohols. No differences were found in cuticle thickness and carbon isotope discrimination in near‐isogenic lines differing at Iw1.
Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and ...efficacy of 24 compounds belonging to chemical group 4 (non‐conjugated and accumulated unsaturated straight‐chain and branched‐chain, aliphatic primary alcohols, aldehydes, acids, acetals and esters). This opinion concerns 23 compounds from this group. They are currently authorised as flavours in food. The FEEDAP Panel established the following conclusions: hex‐3(cis)‐en‐1‐ol 02.056, (Z)‐non‐6‐en‐1‐ol 02.093, oct‐3‐en‐1‐ol 02.094, non‐6(cis)‐enal 05.059, hex‐3(cis)‐enal 05.075, (Z)‐hept‐4‐enal 05.085, hex‐3(cis)‐enyl acetate 09.197, hex‐3(cis)‐enyl formate 09.240, hex‐3‐enyl butyrate 09.270, hex‐3‐enyl hexanoate 09.271 and hex‐3(cis)‐enyl isobutyrate 09.563 are safe at the proposed maximum use level of 5 mg/kg complete feed for all target species; citronellol 02.011, (‐)‐3,7‐dimethyl‐6‐octen‐1‐ol 02.229, citronellal 05.021, 2,6‐dimethylhept‐5‐enal 05.074, citronellic acid 08.036, citronellyl acetate 09.012, citronellyl butyrate 09.049, citronellyl formate 09.078 and citronellyl propionate 09.129 are safe at the maximum use level of 5 mg/kg for all species, except cats for which the proposed normal use level of 1 mg/kg is considered safe; undec‐10‐enal 05.035, 1‐ethoxy‐1‐(3‐hexenyloxy)ethane 06.081 and hex‐3‐enyl isovalerate 09.505 are safe at the normal use levels of 1 mg/kg for all species. No safety concern would arise for the consumer from the use of these compounds up to the highest safe level in feeds. Hazards for skin and eye contact, and respiratory exposure are recognised for the majority of the compounds under application. Most are classified as irritating to the respiratory system. The use of the majority of the compounds in animal feed at the maximum safe level is considered safe for the environment. As all the compounds under assessment are used in food as flavourings, and their function in feed is essentially the same as in food, no further demonstration of efficacy is necessary.
The densities (ρ), viscosities (η), and speeds of sound (u) were reported for binary mixtures of 2-ethyl-1-hexanol with aliphatic primary alcohols (propan-1-ol, 2-propen-1-ol, 2-propyn-1-ol) over the ...entire composition range from 303.15 K to 313.15 K and at atmospheric pressure 0.1 MPa. The excess parameters (V
E
,κ
s
E
), deviation in viscosity, excess partial molar volumes, (
and
) excess partial molar isentropic compressibility's (
and
) of the components at infinite dilution were calculated from the densities, speeds of sound, and viscosities at experimental temperatures. The variation of these properties with composition of the mixtures suggests hydrogen bond and charge-transfer complex formation between 2-ethyl-1-hexanol and self-associated primary alcohols. The V
E
results have been analysed in the light of Prigogine-Flory-Patterson theory. An analysis of each of the three contributions, namely, interactional, free volume and P* to V
E
shows that interactional contribution was positive for all binary systems. The free volume effect and P* contribution were negative for all the mixtures. Furthermore, the FTIR spectra have been recorded at 298.15 K and found to be useful for understanding the presence of hydrogen bonding between dissimilar molecules in the liquid mixtures. A good agreement was obtained between excess quantities and spectroscopic data.
A new strategy for the sequential C–H oxidation/asymmetric phosphonylation of primary alcohols has been developed. It involves a combination of Cu(I)/TEMPO/NMI (N-methylimidazole) oxidation, under an ...air atmosphere, with chiral Al (salalen)-catalyzed enantioselective addition. Various primary alcohols, including benzylic alcohols, allylic alcohols, propargylic alcohols, alkyl alcohols, and other alcohols containing oxygen-, sulfur-, and nitrogen-heterocycles were smoothly converted into chiral α-hydroxy phosphonates with good yields and high enantioselectivities. Inhibitor of CD45 and a plant growth regulator can be easily synthesized by this new method.
A new strategy for the sequential C–H oxidation/asymmetric phosphonylation of primary alcohols has been developed. Various alcohols were smoothly converted into chiral α-hydroxy phosphonates with good yields and high enantioselectivities. Display omitted .
PDF
