TfOH-Catalyzed Formal [3 + 2] Cycloaddition of Cyclopropane 1,1-Diesters with Nitriles

A triflic acid-catalyzed formal [3 + 2] cycloaddition of cyclopropane 1,1-diesters with nitriles was developed. This reaction was expeditious, and the scope of the substituents in both cyclopropanes and nitriles was broad. This supplies an efficient and practical method for the synthesis of 1-pyrrolines

Cooperative Photo-/Lewis Acid Catalyzed Tandem Intramolecular [3 + 2] Cross-Cycloadditions of Cyclopropane 1,1-Diesters with α,β-Unsaturated Carbonyls for Medium-Sized Carbocycles

A tandem isomerization/intramolecular [3 + 2] cross-cycloaddition (IMCC) of cyclopropane 1,1-diesters with α,β-unsaturated ketones/aldehydes under a cooperative catalysis of photo and Lewis acids has been successfully developed. This supplied a general and efficient strategy for construction of medium-sized carbocyclic (8-, 9-, and 10-membered) skeletons as well as such carbocycle-based bridged oxa-bicyclo­[<i>n</i>.2.1] (<i>n</i> = 4–6) skeletons

Lewis Acid Catalyzed Formal Intramolecular [3 + 3] Cross-Cycloaddition of Cyclopropane 1,1-Diesters for Construction of Benzobicyclo[2.2.2]octane Skeletons

A novel Lewis acid catalyzed formal intramolecular [3 + 3] cross-cycloaddition (IMCC) of cyclopropane 1,1-diesters has been successfully developed. This supplies an efficient and conceptually new strategy for construction of bridged bicyclo[2.2.2]­octane skeletons. This [3 + 3]­IMCC could be run up to gram scale and from easily prepared starting materials. This [3 + 3]­IMCC, together with our previously reported [3 + 2]­IMCC strategy, can afford either the bicyclo[2.2.2]­octane or bicyclo[3.2.1]­octane skeletons from the similar starting materials by regulating the substituents on vinyl group

Lewis Acid Catalyzed Intramolecular [3 + 2] Cross Cycloadditions of Cobalt-Alkynylcyclopropane 1,1-Diesters with Carbonyls for Construction of Medium-Sized and Polycyclic Skeletons

A Lewis acid catalyzed intramolecular [3 + 2] cross cycloaddition of cobalt-alkynylcyclopropane 1,1-diesters with carbonyls has been successfully developed. Together with simple and efficient postcycloadditions of the cobalt-alkyne moiety, a general and efficient strategy for construction of structurally complex and diverse medium-sized skeletons and related polycycles was supplied successfully

DataSheet1_Analysis of heavy metals in the conversion of lake sediment and restaurant waste by black soldier fly (Hermetia illucens).xlsx

The risk posed by heavy metals makes it difficult to dispose of sediment contaminants from dredging lakes in China. Black soldier fly (Hermetia illucens) can convert organic waste, such as restaurant waste and lake sediment, to high-value-added protein feed and fertilizer. Experimental groups were formed in this study to explore the conversion of heavy metals present in the mixture of restaurant waste and lake sediment by black soldier fly larvae (BSFL). The results demonstrated that BSFL could survive in pure sediment with an 84.76% survival rate. Relative to the substrate, BSFL could accumulate 70-90% zinc (Zn), chromium (Cr), copper (Cu), and 20-40% cadmium (Cd) and lead (Pb). The experimental group 2:3, with 40% lake sediment and 60% restaurant waste, was the best group after conversion for 15 days, which showed a 95.24% survival rate of BFSL, 82.20 mg average weight of BFSL, 8.92 mm average length of BFSL, with varying content of heavy metals such as Cu (43.22 mg/kg), Zn (193.31 mg/kg), Cd (1.58 mg/kg), Cr (25.30 mg/kg) Cr, and Pb (38.59 mg/kg) in BSFL. Furthermore, the conversion residue conforms to the relevant standards of organic fertilizer in China and can be used as organic fertilizer. Overall, the present study shows that black soldier flies can improve the resource utilization of lake sediment, especially by reducing the effect of heavy metals.</p

Total Syntheses of (−)-Englerins A/B, (+)-Orientalols E/F, and (−)-Oxyphyllol

(−)-Englerin A was synthesized in 20 steps from the commercially available material (<i>R</i>)-(+)-limonene. In addition, (−)-englerin B, (+)-orientalol E/F and (−)-oxyphyllol were obtained from the intermediate in the route. The key steps include a hydroxyl-directing stereoselective and regioselective intramolecular cyclopropanation and a multi-gram-scale stereoselective formal intramolecular [3 + 2] cross cycloaddition ([3 + 2]-IMCC) of a cyclopropane 1,1-diester with a carbonyl. A precursor of 7,10-diastereoisomer of englerins was also obtained

Plot showing absence of correlation between soluble Cr levels in hand-washing samples and children’s age for both CCA and non-CCA playgrounds

<p><b>Copyright information:</b></p><p>Taken from "Chromium on the Hands of Children After Playing in Playgrounds Built from Chromated Copper Arsenate (CCA)–Treated Wood"</p><p>Environmental Health Perspectives 2005;114(3):460-465.</p><p>Published online 6 Oct 2005</p><p>PMCID:PMC1392243.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p> Results are for Cr levels (ng) as determined by ICP-MS analysis of the hand-washings of 63 children who played in eight CCA and 64 children who played in eight non-CCA playgrounds. Correlation coefficients are = 0.24 (CCA: = 104 + 611) and = 0.35 (non-CCA: = 86 + 241)