Biochemical evaluation of interactions between synergistic molecules and phase I enzymes involved in insecticide resistance in B- and Q-type Bemisia tabaci (Hemiptera: Aleyrodidae)

BACKGROUND Metabolic resistance is an important consideration in the whitefly Bemisia tabaci, where an esterase‐based mechanism has been attributed to pyrethroid resistance and over‐expression of the cytochrome P450, CYP6CM1, has been correlated to resistance to imidacloprid and other neonicotinoids. RESULTS In vitro interactions between putative synergists and CYP6CM1, B and Q‐type esterases were investigated, and structure–activity relationship analyses allowed the identification of chemical structures capable of acting as inhibitors of esterase and oxidase activities. Specifically, methylenedioxyphenyl (MDP) moieties with a polyether chain were preferable for optimum inhibition of B‐type esterase, whilst corresponding dihydrobenzofuran structures were potent for the Q‐esterase variation. Potent inhibition of CYP6CM1 resulted from structures which contained an alkynyl chain with a terminal methyl group. CONCLUSIONS Synergist candidates could be considered for field control of B. tabaci, especially to abrogate neonicotinoid resistance. © 2017 Society of Chemical Industr

Functionalization of phosphazenes.VII. Photooxidative stabilization of aryloxy-substituted poluorganophosphazenes induced by grafting HALS groups through anhydride moieties

In this article, the general procedure for stabilizing polyorganophosphazenes against the damage induced in these substrates by photooxidation reactions under accelerated conditions is explored. This method is based on the preventive grafting of succinic anhydride groups onto selected polyphosphazenes induced by light excitation, followed by the reaction of the functionalized phosphazene substrates with amino-terminated HALS groups. HALS moieties, in fact, are able to strongly inhibit the photooxidation of phosphazene films under accelerated conditions even when randomly attached to the polyphosphazene materials in very low amounts

GREEN METRICS: COMPARATIVE ASSESSMENT OF AN ALTERNATIVE SYNTHESIS OF 5-BENZYL-3-FURFURYL ALCOHOL, A KEY INTERMEDIATE FOR THE PRODUCTION OF RESMETHRINS

Pyrethroids are synthetic insecticides possessing greater insecticidal potency and enhanced photostability than plant-derived pyrethrins. Thanks to their low mammalian toxicity and biodegradability, they emerged as a replacement for DDT since the late \u201960. The demand for pyrethoids is increasing, also due to the upgraded agriculture technologies of \u201cemerging countries\u201d such as China. Resmethrin was one of the first members of the pyrethroid family to be used. Available preparations of 3 pose an heavy burden on the environment. We present here an alternative route to 1, that avoids the use of 3. A comparative quantitative assessment of the \u201cgreenness\u201d of the process will also be shown. Among the several metrics available, we chose to use EATOS ( ) which takes into account both the mass economy and the environmental impact of the materials involved. The assessment was made using a freeware software, available from the authors (6), that produces readily comparable charts

Introducing green metrics early in process development. Comparative assessment of alternative industrial routes to Elliott\u2019s alcohol, a key intermediate in the production of resmethrins.

A comparative assessment between two alternative routes to Elliot\u2019s alcohol, an industrial intermediate in the preparation of pyrethroids of the resmethrin family, is presented in this section. This assessment is made with the aid of the EATOS tool and takes into consideration both the masses (E-factor) as well as environmental impact of the substances employed and released by the processes (Sheldon\u2019s Q)

Process for preparing enriched enantiomers of 3-(Benzo[1,3]dioxol-5-yl)-2-methylpropanal

A process is described for preparing enriched enantiomers of the compound 3-(benzo[1,3]dioxol-5-yl)-2-methylpropanal of formula (I) comprising the following steps: i) reacting the racemic compound 3-(benzo[1,3]dioxol-5-yl)-2-methylpropanol (2) with phthalic anhydride to give the racemic acid (3); ii) resolving the racemic acid (3) with optically active 1-aryl-1-ethanamine (4) in which Ar is an aromatic or heteroaromatic group having from 6 to 12 members optionally substituted with one or more substituents chosen from the group consisting of (C 1 -C 3 ) alkyl, (C 1 -C 3 ) alkoxy and halogen; iii) recovering the (S)-(2) and (R)-(2) alcohols from the resolved acids (3) of step ii) by alkaline hydrolysis; iv) converting the (S)-2 and (R)-2 alcohols into the respective (S) and (R) enantiomers of compound (I)

38. A new economical and environmentally friendly synthesis of 2,5-dimethyl-2,4-hexadiene

A new vapor phase process for the synthesis of 2,5-dimethyl-2,4-hexadiene (or tetramethyl-butadiene) by dehydration of 2,5-dimethyl-2,4-hexadiiol on solid acid catalysts is described. This synthesis is an interesting example of an economical and environmentally friendly process of industrial interest