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esters, etc ; agricultural pollution; bioavailability; biogeochemical cycles; lakes; nuclear magnetic resonance spectroscopy; organic matter; orthophosphates; pH; principal component analysis; risk; rivers; sediments; China; Show all 14 Subjects
Abstract:
... Phosphorus (P) in sediments plays an important role in shallow lake ecosystems and has a major effect on the lake environment. The mobility and bioavailability of P primarily depend on the contents of different P forms, which in turn depend on the sedimentary environment. Here, sediment samples from Baiyangdian (BYD) lake were collected and measured by the Standards, Measurements, and Testing proc ...
... An efficient and mild cascade reaction of acryloylbenzamides with N-hydroxyphthalimide (NHPI) esters is disclosed. It goes through radical addition and subsequent cyclization to give 4-alkylated isoquinolinediones in the presence of visible light and photocatalyst Ir[dF(CF₃)ppy₂](dtbbpy)PF₆. ...
... An efficient seven-step procedure is described for the synthesis of (25R)-cholesta-5,7-diene-3β,26-diol from commercially available ergosterol in an overall yield of 25%. The synthesis features Julia-Kocienski olefination of the aldehyde with benzothiazole sulfone ester in presence of LiHMDS followed by reduction of the alkene. ...
esters, etc ; derivatization; stereoselective synthesis; Show all 3 Subjects
Abstract:
... The cyclopropanation of alkenyl boronates and subsequent derivatization of the boronate handle are a convenient strategy to quickly build molecular complexity and access diverse compounds with a high sp³ fraction. Herein, we describe the asymmetric cyclopropanation of enantioenriched hydrobenzoin-derived alkenyl boronic esters toward the synthesis of tertiary and secondary cyclopropyl boronates. ...
... A palladium-catalyzed radical cascade cyanoalkylsulfonylation/cyclization of 3-arylethynyl-[1,1′-biphenyl]-2-carbonitriles with DABCO·(SO₂)₂ and cyclobutanone oxime esters via cleavage of a C–C single bond and insertion of SO₂ was described. A series of cyanoalkylsulfone-containing cyclopenta[gh]phenanthridines were obtained in moderate-to-good yields, thus featuring mild reaction conditions, a br ...
... We report the transition-metal-free defluorinative C–C bond-forming reaction of trifluoromethyl alkenes with gem-(diborylalkyl)lithiums. This synthetic strategy provides access to a variety of 4,4-difluoro homoallylic diboronate esters, which serve as versatile intermediates in the efficient preparation of valuable gem-difluoroalkene derivatives. Further synthetic modifications are conducted to de ...
... This review paper provides an overview of the main strategies for the oxidative esterification of thiols with alcohols. The review is divided into two major parts according to final products. The first includes the methods for the synthesis of sulfinic esters, while the second contains the procedures for the fabrication of sulfonic ester derivatives. ...
... Vinylboronic esters and allylboronic esters are well known to afford olefins by protodeboronation, and therefore homoallenylboronic esters should be similarly available as precursors for 1,3-dienes, but this strategy has not been well explored due to the limited availability of homoallenylboronic esters. Here, we describe a versatile synthesis of homoallenylboronic esters via lithiation–borylation ...
esters, etc ; alkenes; chemical communication; regioselectivity; Show all 4 Subjects
Abstract:
... A palladium-catalyzed intermolecular alkynylcarbonylation of unactivated alkenes has been established with ethynyl benziodoxolones (EBXs) as alkynylation reagents, providing β-alkynylcarboxylic esters efficiently from simple alkenes. The reaction features moderate to excellent regioselectivity and excellent functional group compatibility under mild reaction conditions. ...
esters, etc ; alkenes; design; methodology; photocatalysis; Show all 5 Subjects
Abstract:
... A series of indole-derived alkenes have been designed and applied in a photocatalytic cascade reaction with bromodifluoroacetate esters, affording an unknown type of tetracyclic tetrahydro-γ-carboline derivative in up to 90% yields. Mechanistic studies suggest that the reaction proceeds with tetrahydro-γ-carboline as a key intermediate. The reaction tolerates a diverse pool of substrates, which pr ...
esters, etc ; colloids; fields; peptides; surfaces; ultrasonics; Show all 6 Subjects
Abstract:
... Peptide derivatives and, most specifically, their self-assembled supramolecular structures are being considered in the design of novel biofunctional materials. Although the self-assembly of triphenylalanine homopeptides has been found to be more versatile than that of homopeptides containing an even number of residues (i.e. diphenylalanine and tetraphenylalanine), only uncapped triphenylalanine (F ...
esters, etc ; catalysts; chemical communication; salting; salts; Show all 5 Subjects
Abstract:
... A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC–Cu catalyst. In addition, the selective cleavage of either alkyl(C)–sulfonyl or aryl(C)–sulfonyl bonds of a cyclic sulfone via Cu-free or Cu-mediated processes generates the corresponding sulfinate salts, which can be further derivatised to provid ...
... Quasi-2D perovskites are potential materials for optoelectronics like light-emitting diodes (LEDs); compared to their 3D counterparts, they are considered more stable against the atmosphere and more efficient in exciton confining. However, the simultaneous formation of different phases in the quasi-2D perovskite film, i.e., the phase impurity issue, lowers the device performance. We propose using ...
esters, etc ; chalcone; journals; ketones; organic chemistry; Show all 5 Subjects
Abstract:
... An NHC-catalyzed [2 + 4] cyclization of alkynyl ester with α,β-unsaturated ketone to form a pyran scaffold was developed successfully. The cheap and easily available starting materials, mild reaction conditions, moderate to excellent yields, and high atom economy make this strategy attractive for the syntheses of highly substituted 4H-pyran derivatives. ...
ortho esters, etc ; antineoplastic agents; glycosides; regioselectivity; research; Show all 5 Subjects
Abstract:
... Convergent synthetic routes to PI-88 tetra- and pentasaccharide-component analogues, have been developed featuring regioselective glycosylations of mannose-polyol n-pentenyl glycosides (NPG) acceptors with 1,2-methyl orthoesters (MeOE) glycosyl donors. ...
esters, etc ; Lewis acids; arylation; hydroxamic acids; methodology; Show all 5 Subjects
Abstract:
... Herein, we describe the nickel-catalyzed reductive arylation of remote C(sp³)–H bonds with aryl electrophiles. The reaction targets secondary and tertiary C(sp³)–H bonds to deliver all-carbon quaternary centers. The success of this method relies on a novel amidyl radical precursor that tolerates reducing conditions, namely O-oxalate hydroxamic acid esters. ...
esters, etc ; amides; amines; blood chemistry; chemical communication; Show all 5 Subjects
Abstract:
... The direct N-acylation of amines by esters in a microreactor is described using argon plasma, thereby producing amides in good to excellent yields. ...
esters, etc ; heterocyclic compounds; journals; ketones; organic chemistry; Show all 5 Subjects
Abstract:
... α-Iodo-α,β-unsaturated ketones such as compound 1 serve as vicinal dielectrophiles and react with a range of dinucleophiles including pentane-2,4-dione and 1,3-indandione to produce [3 + 2]- and [2 + 1]-adducts such as 5 and 38, respectively. [4 + 2]- and [5 + 2]-cycloadducts have been obtained from compound 1 by related means. Preliminary studies reveal that α-iodinated α,β-unsaturated esters can ...
esters, etc ; catalytic activity; diazo compounds; indium; methodology; yields; Show all 6 Subjects
Abstract:
... One-carbon-unit insertion into carbon–halogen (C–X) bonds accompanied by the formation of a new C–X bond and carbon–chain elongation is a powerful synthetic method of complex organohalides. Herein, we developed an indium trihalide catalyzed formal insertion of diazo esters into a C–X (X = Cl, Br, I) bond. In the present system, the reactions of α-aryl diazo esters with benzylic chlorides, bromides ...