Sequential One-Pot Research Articles

Sequential One-Pot Ruthenium-Catalyzed Azide−Alkyne Cycloaddition from Primary Alkyl Halides and Sodium Azide

An experimentally simple sequential one-pot RuAAC reaction, affording 1,5-disubstituted 1H-1,2,3-triazoles in good to excellent yields starting from an alkyl halide, sodium azide, and an alkyne, is reported. The organic azide is formed in situ by treating the primary alkyl halide with sodium azide in DMA under microwave heating. Subsequent addition of [RuClCp*(PPh(3))(2)] and the alkyne yielded the desired cycloaddition product after further microwave irradiation.

Sequential One-Pot Combination of Multireactions through Multicatalysis: A General Approach to Rapid Assembly of Functionalized Push−Pull Olefins, Phenols, and 2-Methyl-2H-chromenes

A general, sustainable and practical process for the sequential cascade one-pot synthesis of library of highly substituted push-pull olefins, phenols and 2-methyl-2H-chromenes was reported through multicatalysis cascade (MCC) reactions. Direct sequential one-pot combination of amine- or amino acid-catalyzed cascade Knoevenagel/Michael/aldol condensation/decarboxylation with other reactions like amine- or amino acid-catalyzed cascade Claisen-Schmidt/iso-aromatization, Claisen-Schmidt/isomerization, Claisen-Schmidt/iso-aromatization/isomerization, Michael addition, Claisen-Schmidt/Michael, ruthenium-base-silica-catalyzed ring closing metathesis/base-induced ring-opening/benzylic oxidation/[1,7]-sigmatropic hydrogen shift, or ruthenium-base-heat-catalyzed ring closing metathesis/base-induced ring-opening/[1,7]-sigmatropic hydrogen shift reactions of alkyl acetoacetates, a variety of aldehydes and alkyl halides furnished the highly functionalized push-pull olefins, phenols and 2-methyl-2H-chromenes with high yields. The yields and regioselectivities were good to excellent. Evidence for a new reaction pathway involving in situ formation of novel push-pull dienamines under amine- or amino acid-catalysis is presented along with examples demonstrating the amenability of the process to MCC chemistry.

Six-Component Reactions for the Stereoselective Synthesis of 3-Arylidene-2-oxindoles via Sequential One-Pot Ugi/Heck Carbocyclization/Sonogashira/Nucleophilic Addition

An efficient palladium-catalyzed protocol for the synthesis of 3-arylidene-2-oxindoles has been developed. In this approach, a sequential one-pot six-component reaction via Ugi/Heck carbocyclization/Sonogashira/nucleophilic addition was used for the synthesis of the desired skeleton.

Three-Component Synthesis of N-Boc-4-iodopyrroles and Sequential One-Pot Alkynylation

(Hetero)aryl-, alkenyl-, and selected alkyl-substituted acid chlorides can be efficiently coupled with N-Boc-protected propargylamine to produce ynones which are converted in a one-pot fashion to 2-substituted N-Boc-4-iodopyrroles. Upon addition of a further alkyne, another Sonogashira coupling can be carried out in a one-pot fashion. This sequentially Pd/Cu-catalyzed process represents a very mild and efficient entry to 2,4-disubstituted N-Boc-pyrroles.

Palladium-Catalyzed Carbon−Sulfur Cross-Coupling Reactions with Indium Tri(organothiolate) and Its Application to Sequential One-Pot Processes

It was found that indium tri(organothiolate) is an effective nucleophilic coupling partner in Pd-catalyzed C-S cross-coupling reactions to produce the functionalized sulfides in excellent yields with high atom efficiency and complete regio- and chemoselectivity. The present method was efficiently applied to the sequential one-pot processes composed of selective double C-S cross-coupling reactions and addition of allylindium or allenylindium to aldedyde to give the functionalized sulfides and bis(sulfides).

Sequential One-Pot Glycosidations Catalytically Promoted: Unprecedented Strategy in Oligosaccharide Synthesis for the Straightforward Assemblage of the Antitumor PI-88 Pentasaccharide

The pentasaccharide sequence of the most active components of the antitumor drug PI-88, currently in phase II clinical trial, has been rapidly assembled in high overall yield and in only three steps starting from three monosaccharide building blocks. The procedure takes advantage of the first reported strategy of sequential one-pot glycosidations conducted exclusively under catalytic activation. In addition, the procedure relies only on shelf-stable and mild promoters such as Yb(OTf)(3) and Bi(OTf)(3).

Organocatalytic Sequential One-Pot Double Cascade Asymmetric Synthesis of Wieland−Miescher Ketone Analogues from a Knoevenagel/Hydrogenation/Robinson Annulation Sequence: Scope and Applications of Organocatalytic Biomimetic Reductions

A practical and novel organocatalytic chemo- and enantioselective process for the cascade synthesis of highly substituted 2-alkyl-cyclohexane-1,3-diones and Wieland-Miescher (W-M) ketone analogs is presented via reductive alkylation as a key step. First time, we developed the one-step alkylation of dimedone and 1,3-cyclohexanedione with aldehydes and Hantzsch ester through an organocatalytic reductive alkylation strategy. Direct combination of l-proline-catalyzed cascade Knoevenagel/hydrogenation and cascade Robinson annulation of CH acids (dimedone and 1,3-cyclohexanedione), aldehydes, Hantzsch ester, and methyl vinyl ketone furnished the highly functionalized W-M ketone analogues in good to high yields and with excellent enantioselectivities. Many of the reductive alkylation products show a direct application in pharmaceutical chemistry.

Synthesis of 3-O-Acylated Epicatechin Derivatives via Sequential One-Pot Multi-Step Reactions

An effective approach for the synthesis of epicatechin derivatives based on sequential one-pot multi-step reactions is described. Reductive etherification of the disulfanyl derivative was promoted with a catalytic amount of TfOH, providing the cis-substituted benzopyran derivative in a stereoselective manner.

Sequential One‐Pot Reactions Using the Concept of “Site Isolation”

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Sequential One‐Pot Reactions Using the Concept of “Site Isolation”

Sequential One‐Pot Reactions Using the Concept of “Site Isolation”

Sequential one-pot glycosylations using 1-hydroxyl and 1-thiodonors.

[reaction: see text] A novel sequential glycosylation procedure is described that combines the use of 1-hydroxyl and thiodonors. The Ph(2)SO/Tf(2)O-mediated dehydrative condensation of 1-hydroxyl donors with thioglycosides affords in good yield the thiodisaccharides, which in turn can be activated by the same activator system to furnish trisaccharides. The alpha-Gal epitope and a hyaluronan trisaccharide were efficiently assembled in a one-pot procedure.

ChemInform Abstract: A Convenient Synthetic Entry into 2,2-Diorganyl-5,6-diaryl-1,3,4,2-dioxaza Silacyclohexene Derivatives via Dianion Cyclization: Sequential One-Pot Cyclosylation.

ChemInform Abstract: A Convenient Synthetic Entry into 2,2-Diorganyl-5,6-diaryl-1,3,4,2-dioxaza Silacyclohexene Derivatives via Dianion Cyclization: Sequential One-Pot Cyclosylation.

Direct Synthesis of Chiral Acetals from Carbonyl Compounds and Chiral Diols: Sequential One-Pot Asymmetric Silylcyanation Reaction Catalyzed by Scandium(III) Triflate

Direct Synthesis of Chiral Acetals from Carbonyl Compounds and Chiral Diols: Sequential One-Pot Asymmetric Silylcyanation Reaction Catalyzed by Scandium(III) Triflate

Sequential One-Pot Aldol Reactions Catalyzed by 2-Deoxyribose-5-phosphate Aldolase and Fructose-1,6-diphosphate Aldolase

Sequential One-Pot Aldol Reactions Catalyzed by 2-Deoxyribose-5-phosphate Aldolase and Fructose-1,6-diphosphate Aldolase

Photoinduced Electron Transfer Initiated Activation of Organoselenium Substrates as Carbocation Equivalents: Sequential One-Pot Selenylation and Deselenylation Reaction

Photoinduced Electron Transfer Initiated Activation of Organoselenium Substrates as Carbocation Equivalents: Sequential One-Pot Selenylation and Deselenylation Reaction