85 research outputs found

    Rhodium(III)-Catalyzed Cascade Cyclization/Electrophilic Amidation for the Synthesis of 3‑Amidoindoles and 3‑Amidofurans

    No full text
    A rhodium­(III)-catalyzed cascade cyclization/electrophilic amidation using <i>N</i>-pivaloyloxylamides as the electrophilic nitrogen source has been developed. This protocol provides an efficient route for the synthesis of 3-amidoindoles and 3-amidofurans under mild conditions with good functional group tolerance. The synthetic utility of this reaction has been demonstrated through the derivatization of the 3-amidoindoles to several heterocycle-fused indoles

    Rhodium(III) Catalyzed Carboamination of Alkenes Triggered by C–H Activation of <i>N</i>‑Phenoxyacetamides under Redox-Neutral Conditions

    No full text
    <i>N</i>-Alkoxyacrylamides are coupled with <i>N</i>-phenoxyacetamides by Rh<sup>III</sup> catalysis through C–H functionalization and amido group transfer under external oxidant-free conditions, which affords acyclic alkene carboamination products in an atom-economical way. Mechanistic insight into this transformation indicates the amide group in <i>N</i>-alkoxyacrylamide plays a critical role in this C–C/C–N bond formation reaction. This methodology provides a highly efficient way to construct <i>o</i>-tyrosine derivatives under mild conditions

    Rhodium(III)-Catalyzed Cascade Cyclization/Electrophilic Amidation for the Synthesis of 3‑Amidoindoles and 3‑Amidofurans

    No full text
    A rhodium­(III)-catalyzed cascade cyclization/electrophilic amidation using <i>N</i>-pivaloyloxylamides as the electrophilic nitrogen source has been developed. This protocol provides an efficient route for the synthesis of 3-amidoindoles and 3-amidofurans under mild conditions with good functional group tolerance. The synthetic utility of this reaction has been demonstrated through the derivatization of the 3-amidoindoles to several heterocycle-fused indoles

    Regiocontrolled Coupling of Aromatic and Vinylic Amides with α‑Allenols To Form γ‑Lactams via Rhodium(III)-Catalyzed C–H Activation

    No full text
    A mild, regiocontrolled coupling of aromatic and vinylic amides with α-allenols to form γ-lactams via rhodium­(III)-catalyzed C–H activation has been demonstrated. This [4 + 1] annulation reaction provides an efficient method for the synthesis of isoindolinones and 1,5-dihydro-pyrrol-2-ones bearing a tetrasubstituted carbon atom α to the nitrogen atom with good functional group tolerance. The hydroxyl group in the allene substrate is essential in controlling the chemo- and regioselectivity of the reaction probably by coordination interaction with the rhodium catalyst

    Rhodium(III) Catalyzed Carboamination of Alkenes Triggered by C–H Activation of <i>N</i>‑Phenoxyacetamides under Redox-Neutral Conditions

    No full text
    <i>N</i>-Alkoxyacrylamides are coupled with <i>N</i>-phenoxyacetamides by Rh<sup>III</sup> catalysis through C–H functionalization and amido group transfer under external oxidant-free conditions, which affords acyclic alkene carboamination products in an atom-economical way. Mechanistic insight into this transformation indicates the amide group in <i>N</i>-alkoxyacrylamide plays a critical role in this C–C/C–N bond formation reaction. This methodology provides a highly efficient way to construct <i>o</i>-tyrosine derivatives under mild conditions

    Manganese-Catalyzed Asymmetric Hydrosilylation of Aryl Ketones

    No full text
    We disclose the synthesis of a series of manganese complexes of chiral iminopyridine oxazoline ligands and their application in the first manganese-catalyzed asymmetric ketone hydrosilylations. The most sterically hindered manganese catalyst bearing two CH­(Ph)<sub>2</sub> groups at the 2,6-ortho positions of the imino aryl ring and a <i>t</i>Bu group on the oxazoline ring furnishes the secondary alcohols in high enantioselectivities and yields

    Cascade Synthesis of 3‑Alkylidene Dihydrobenzofuran Derivatives via Rhodium(III)-Catalyzed Redox-Neutral C–H Functionalization/Cyclization

    No full text
    An efficient rhodium­(III)-catalyzed coupling reaction of <i>N</i>-phenoxyacetamides with propargyl carbonates to yield 3-alkylidene dihydrobenzofuran derivatives via C–H functionalization/cascade cyclization has been developed. This transformation represents a redox-neutral process and features the formation of three new bonds under mild conditions

    Rhodium(III)-Catalyzed C–H Olefination for the Synthesis of <i>ortho</i>-Alkenyl Phenols Using an Oxidizing Directing Group

    No full text
    By using an oxidizing directing group, a mild, efficient Rh(III) catalyzed C–H olefination reaction between <i>N</i>-phenoxyacetamides and alkenes was developed. This reaction provided a straightforward way for the synthesis of <i>ortho</i>-alkenyl phenols, and the directing group is traceless in the product

    Ruthenium-Catalyzed Site-Selective Intramolecular Silylation of Primary C–H Bonds for Synthesis of Sila-Heterocycles

    No full text
    Incorporating the silicon element into bioactive organic molecules has received increasing attention in medicinal chemistry. Moreover, organosilanes are valuable synthetic intermediates for fine chemicals and materials. Transition metal-catalyzed C–H silylation has become an important strategy for C–Si bond formations. However, despite the great advances in aromatic C­(sp<sup>2</sup>)–H bond silylations, catalytic methods for aliphatic C­(sp<sup>3</sup>)–H bond silylations are relatively rare. Here we report a pincer ruthenium catalyst for intramolecular silylations of various primary C­(sp<sup>3</sup>)–H bonds adjacent to heteroatoms (O, N, Si, Ge), including the first intramolecular silylations of C–H bonds α to O, N, and Ge. This method provides a general, synthetically efficient approach to novel classes of Si-containing five-membered [1,3]-sila-heterocycles, including oxasilolanes, azasilolanes, disila-heterocycles, and germasilolane. The trend in the reactivity of five classes of C­(sp<sup>3</sup>)–H bonds toward the Ru-catalyzed silylation is elucidated. Mechanistic studies indicate that the rate-determining step is the C–H bond cleavage involving a ruthenium silyl complex as the key intermediate, while a η<sup>2</sup>-silene ruthenium hydride species is determined to be an off-cycle intermediate

    The performance of difference inference methods in the external validation set of GPCRs and kinases.

    No full text
    <p>All performances were evaluated based on top 20 predicted lists. NBI, network-based inference; NWNBI, node weighted network-based inference; EWNBI, edge weighted network-based inference; DBSI-T, drug-based similarity inference with Tanimoto similarity score; DBSI-C, DBSI with Cosine similarity score; DBSI-F, DBSI with Forbes similarity score; DBSI-R, DBSI with Russell-rao similarity score; TBSI, target-based similarity inference; R, recall; ER, recall enhancement; AUC, the area under the receiver operating characteristic curve; C<sub>i</sub> (P<sub>a</sub>, P<sub>b</sub>, …, P<sub>m</sub>) represents the prioritization of new targets for a given chemical; P<sub>j</sub> (C<sub>a</sub>, C<sub>b</sub>, …, C<sub>n</sub>) represents the prioritization of new chemicals for a given protein.</p
    • …
    corecore