A Convenient Preparation of 5-Iodo-1,4-disubstituted-1,2,3-triazole: Multicomponent One-Pot Reaction of Azide and Alkyne Mediated by CuI−NBS

The system of CuI and NBS was found to provide both I+ and Cu+ for the first time. An efficient method for preparation of 5-iodo-1,4-disubstituted-1,2,3-triazole was achieved by multicomponent one-pot reaction of azides with alkynes in the presence of the novel CuI and NBS catalytic system. The high tolerance of various sensitive groups revealed the potential applications of this method in organic synthesis and drug discovery

Approach to Polysubstituted 4‑Pyridones from <i>N</i>‑Aryl Acetoacetamides via a <i>N</i> to <i>C</i> 1,3-Acyl Migration Mediated by Sodium Persulfate

Mediated by sodium persulfate (Na₂S₂O₈), a series of polysubstituted 4-pyridones were synthesized via self-condensation of <i>N</i>-aryl acetoacetamides, during which a novel <i>N</i> to <i>C</i> 1,3-acyl migration should be involved. The structure of 4-pyridone was unequivocally confirmed by X-ray diffraction analysis. However, the self-condensation of <i>N</i>-benzyl acetoacetamides under the same condition gave polysubstituted 2-pyridones instead of 4-pyridones

Approach to Polysubstituted 4‑Pyridones from <i>N</i>‑Aryl Acetoacetamides via a <i>N</i> to <i>C</i> 1,3-Acyl Migration Mediated by Sodium Persulfate

Mediated by sodium persulfate (Na2S2O8), a series of polysubstituted 4-pyridones were synthesized via self-condensation of N-aryl acetoacetamides, during which a novel N to C 1,3-acyl migration should be involved. The structure of 4-pyridone was unequivocally confirmed by X-ray diffraction analysis. However, the self-condensation of N-benzyl acetoacetamides under the same condition gave polysubstituted 2-pyridones instead of 4-pyridones

Derivation and Properties of Recombinant Fab Antibodies to the Phenylurea Herbicide Diuron

The Fab domain sequences from messenger RNA of a mouse hybridoma cell line secreting a monoclonal antibody (MAb) specific for the phenylurea herbicide diuron were amplified and inserted into the M13 phagemid vector pComb8. Phage displaying diuron-specific Fab fragments were selected by binding to magnetic beads coated with diuron hapten conjugates, and eluted with diuron. Soluble rFab in E. coli lysates bound diuron with half-maximal inhibition (I50) of 1.6−12 ppb (ng/mL) in indirect and direct competition enzyme immunoassays (EIAs). The optimal competing hapten was different for indirect EIAs with proteolytic or recombinant Fabs and the intact MAb. Selectivity of rFabs for phenylureas was similar to that of the original MAb and its proteolytic Fab fragment and was not significantly affected by exchange of heavy and light chains among rFab clones, indicating that a single antibody species had been cloned. Keywords: Immunoassay; recombinant antibodies; monoclonal antibodies; diuron; herbicide; phenylurea; arylurea</i

Acylamino-Directed Specific Sequential Difunctionalizations of Anilides via Metal-Free Relay Reactions for <i>p</i>‑Oxygen and <i>o</i>‑Nitrogen Incorporation

Novel acylamino-directed relay disubstitutions realize the sequential difunctionalizations of anilides (1) under mild and metal-free conditions for the first time. This [bis­(trifluoroacetoxy)­iodo]­benzene (PIFA) and BF3·Et2O promoted straightforward reaction produces a series of p-acetoxyl- or p-alkoxyl-o-nitro-N-arylamides (2), which are key scaffolds of various drugs, functional materials, and bioactive molecules. The flexibility with respect to the functional groups in these products affords this novel protocol excellent versatility for synthetic applications

Derivation and Properties of Recombinant Fab Antibodies to the Phenylurea Herbicide Diuron

The Fab domain sequences from messenger RNA of a mouse hybridoma cell line secreting a monoclonal antibody (MAb) specific for the phenylurea herbicide diuron were amplified and inserted into the M13 phagemid vector pComb8. Phage displaying diuron-specific Fab fragments were selected by binding to magnetic beads coated with diuron hapten conjugates, and eluted with diuron. Soluble rFab in E. coli lysates bound diuron with half-maximal inhibition (I50) of 1.6−12 ppb (ng/mL) in indirect and direct competition enzyme immunoassays (EIAs). The optimal competing hapten was different for indirect EIAs with proteolytic or recombinant Fabs and the intact MAb. Selectivity of rFabs for phenylureas was similar to that of the original MAb and its proteolytic Fab fragment and was not significantly affected by exchange of heavy and light chains among rFab clones, indicating that a single antibody species had been cloned. Keywords: Immunoassay; recombinant antibodies; monoclonal antibodies; diuron; herbicide; phenylurea; arylurea</i

Iron-Catalyzed Vinylogous Aldol Condensation of Biginelli Products and Its Application toward Pyrido[4,3‑<i>d</i>]pyrimidinones

A novel iron-catalyzed vinylogous aldol condensation of Biginelli products with aryl aldehydes has been developed for the syntheses of potential bioactive (E)-6-arylvinyl-dihydropyrimidin-2­(1H)-ones. These materials are valuable synthetic precursors to drug-like pyrido­[4,3-d]­pyrimidine derivatives. The amide group at the 5-position of the dihydropyrimidin-2­(1H)-ones played an important role in the vinylogous aldol condensation reaction

Acylamino-Directed Specific Sequential Difunctionalizations of Anilides via Metal-Free Relay Reactions for <i>p</i>‑Oxygen and <i>o</i>‑Nitrogen Incorporation

Novel acylamino-directed relay disubstitutions realize the sequential difunctionalizations of anilides (1) under mild and metal-free conditions for the first time. This [bis­(trifluoroacetoxy)­iodo]­benzene (PIFA) and BF3·Et2O promoted straightforward reaction produces a series of p-acetoxyl- or p-alkoxyl-o-nitro-N-arylamides (2), which are key scaffolds of various drugs, functional materials, and bioactive molecules. The flexibility with respect to the functional groups in these products affords this novel protocol excellent versatility for synthetic applications

Copper-Mediated Radical-Induced Ring-Opening Relay Cascade Carboannulation Reaction of [60]Fullerene with Cyclobutanone Oxime Esters: Access to [60]Fullerene-Fused Cyclopentanes

An unexpected copper-mediated radical-induced ring-opening relay cascade carboannulation reaction of [60]fullerene with cyclobutanone oxime esters is presented for the preparation of various Cl-/Br-incorporated [60]fullerene-fused cyclopentanes. The unique relay cascade transformation uses inexpensive copper salts as promoters and halogen sources and features simple redox-neutral conditions and a broad substrate scope, providing a practical access to a class of novel five-membered carbocycle-fused fullerenes