Browse
Submit Data
Databases
API
Help

Dataset Information

25 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Connective synthesis of 5,5-disubstituted hydantoins by tandem ?-amination and ?-arylation of silyl ketene acetals.

ABSTRACT: 5,5-Disubstituted hydantoins, formally the cyclisation products of quaternary amino acids, were formed connectively from simple ester-derived starting materials by a one-pot tandem method. Amination of the silyl ketene acetal derivative of a methyl ester takes place by silver-catalysed addition to the N[double bond, length as m-dash]N bond of an azocarboxamide, generating a N-amino-N'-aryl urea derivative of a substituted aminoester. Treatment with a base forms an ester enolate which undergoes arylation by intramolecular migration of an aryl ring to the ?-position of the ester. The product undergoes ring closure to a hydantoin, which may itself be deprotected and functionalised. Aryl migration is successful with rings of various electronic character and with esters bearing functionalised and unfunctionalised chains, and the products have features in common with several bioactive compounds.

SUBMITTER: Saunthwal RK

PROVIDER: S-EPMC6429467 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Connective synthesis of 5,5-disubstituted hydantoins by tandem α-amination and α-arylation of silyl ketene acetals.

Saunthwal Rakesh K RK Cornall Matthew T MT Abrams Roman R Ward John W JW Clayden Jonathan J

Chemical science 20190206 11

5,5-Disubstituted hydantoins, formally the cyclisation products of quaternary amino acids, were formed connectively from simple ester-derived starting materials by a one-pot tandem method. Amination of the silyl ketene acetal derivative of a methyl ester takes place by silver-catalysed addition to the N[double bond, length as m-dash]N bond of an azocarboxamide, generating a <i>N</i>-amino-<i>N</i>'-aryl urea derivative of a substituted aminoester. Treatment with a base forms an ester enolate whi ...[more]

PMID: 30996929

Similar Datasets

Enantioselective acylation of silyl ketene acetals through fluoride anion-binding catalysis.

Project description:A highly enantioselective acylation of silyl ketene acetals with acyl fluorides has been developed to generate useful ?,?-disubstituted butyrolactone products. This transformation is promoted by a new thiourea catalyst and 4-pyrrolidinopyridine and represents the first example of enantioselective thiourea anion-binding catalysis with fluoride.

| S-EPMC3164931 | biostudies-literature

Highly enantioselective Mannich reactions with ?-aryl silyl ketene acetals and imines.

Project description:Mannich reactions with chiral silicon Lewis acid activated acylhydrazones and ?-aryl silyl ketene acetals and ?-aryl,?-alkyl silyl ketene imines proceed efficiently and with good to excellent levels of both diastereoselectivity and enantioselectivity. The reactions provide access to ?-aryl,?-hydrazido esters and ?-aryl,?-alkyl,?-hydrazido nitriles, which are valuable analogs of ?-amino acids.

| S-EPMC3042282 | biostudies-literature

Iridium-Catalyzed Enantioselective Allylic Substitution of Aliphatic Esters with Silyl Ketene Acetals as the Ester Enolates.

Project description:Enantioselective allylic substitution with enolates derived from aliphatic esters under mild conditions remains challenging. Herein we report iridium-catalyzed enantioselective allylation reactions of silyl ketene acetals, the silicon enolates of esters, to form products containing a quaternary carbon atom at the nucleophile moiety and a tertiary carbon atom at the electrophile moiety. Under relatively neutral conditions, the allylated aliphatic esters were obtained with excellent regioselectivity and enantioselectivity. These products were readily converted into primary alcohols, carboxylic acids, amides, isocyanates, and carbamates, as well as tetrahydrofuran and ?-butyrolactone derivatives, without erosion of enantiomeric purity.

| S-EPMC5677530 | biostudies-literature

Silyl Ketene Acetals/B(C?F?)? Lewis Pair-Catalyzed Living Group Transfer Polymerization of Renewable Cyclic Acrylic Monomers.

Project description:This work reveals the silyl ketene acetal (SKA)/B(C?F?)? Lewis pair-catalyzed room-temperature group transfer polymerization (GTP) of polar acrylic monomers, including methyl linear methacrylate (MMA), and the biorenewable cyclic monomers ?-methyl-?-methylene-?-butyrolactone (MMBL) and ?-methylene-?-butyrolactone (MBL) as well. The in situ NMR monitored reaction of SKA with B(C?F?)? indicated the formation of Frustrated Lewis Pairs (FLPs), although it is sluggish for MMA polymerization, such a FLP system exhibits highly activity and living GTP of MMBL and MBL. Detailed investigations, including the characterization of key reaction intermediates, polymerization kinetics and polymer structures have led to a polymerization mechanism, in which the polymerization is initiated with an intermolecular Michael addition of the ester enolate group of SKA to the vinyl group of B(C?F?)?-activated monomer, while the silyl group is transferred to the carbonyl group of the B(C?F?)?-activated monomer to generate the single-monomer-addition species or the active propagating species; the coordinated B(C?F?)? is released to the incoming monomer, followed by repeated intermolecular Michael additions in the subsequent propagation cycle. Such neutral SKA analogues are the real active species for the polymerization and are retained in the whole process as confirmed by experimental data and the chain-end analysis by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). Moreover, using this method, we have successfully synthesized well-defined PMMBL-b-PMBL, PMMBL-b-PMBL-b-PMMBL and random copolymers with the predicated molecular weights (Mn) and narrow molecular weight distribution (MWD).

| S-EPMC6017534 | biostudies-literature

Synthesis of 5,5-disubstituted butenolides based on a Pd-catalyzed gamma-arylation strategy.

Project description:Methods for the construction of quaternary carbon centers are of great interest to synthetic chemists due to their presence in natural products. Development of the Pd-catalyzed arylation of butenolides with high selectivity for the gamma-position allows for a facile construction of quaternary centers. The preparation of a wide variety of gamma-aryl butenolides containing a number of functional groups is outlined. An application of this chemistry for a one-pot synthesis of a tricyclic tetrahydroisoquinolinone is demonstrated.

| S-EPMC2739656 | biostudies-literature

Diastereoselective Prins-type reaction of cycloalkenylcyclopropanol silyl ethers and alpha,beta-unsaturated aldehyde acetals.

Project description:Electrophilic addition of 1-(1-cyclohexenyl)-1-cyclopropanol trimethylsilyl ether to alpha,beta-unsaturated aldehyde acetals under Lewis acidic conditions proceeds with good to excellent diastereoselectivity to afford spirocyclobutanones containing three contiguous stereocenters. A convenient entry to enantioselective syntheses is available by use of a nonracemic C2-symmetric acetal. Elaboration of the resulting adducts provides ready access to medium-sized carbocycles.

| S-EPMC2597285 | biostudies-literature

Synthesis of Highly Functionalized 2-Pyranone from Silyl Ketene.

Project description:We report a highly functionalized 2-pyranone small molecule prepared from tert-butyl diphenyl silyl ketene using an alkoxide catalyst and thermally induced rearrangement. Treatment of the silyl ketene with a substoichiometric amount of alkoxide led to the formation of a trimer which was isolated and fully characterized; heating this trimer in a 1,4-dioxane solution induced a thermal rearrangement, yielding the product 2-pyranone. The isolated intermediate and product are characterized by 1D and 2D nuclear magnetic resonance (NMR) spectroscopies, mass spectrometry, and single crystal X-ray diffraction. A mechanism for the thermally induced rearrangement is proposed based on 1H NMR studies, and a rate law is derived from the proposed mechanism with steady-state approximation. This work illustrates a route for the formation of highly functionalized and modifiable 2-pyranone motifs with potential biological activity. The formation of the trimer, and thus the functionalized 2-pyranone, is highly dependent on the silyl substituents and alkoxide counterion and thus indicates the intriguing reactivity of highly functionalized small molecules.

| S-EPMC6645212 | biostudies-literature

Cu-catalyzed N-3-Arylation of Hydantoins Using Diaryliodonium Salts.

Project description:A general Cu-catalyzed, regioselective method for the N-3-arylation of hydantoins is described. The protocol utilizes aryl(trimethoxyphenyl)iodonium tosylate as the arylating agent in the presence of triethylamine and a catalytic amount of a simple Cu-salt. The method is compatible with structurally diverse hydantoins and operates well with neutral aryl groups or aryl groups bearing weakly donating/withdrawing elements. It is also applicable for the rapid diversification of pharmaceutically relevant hydantoins.

| S-EPMC7309330 | biostudies-literature

5,5'-Bis[(trimethyl-silyl)meth-yl]-2,2'-bipyridine.

Project description:The mol-ecule of the title compound, C(18)H(28)N(2)Si(2), occupies a special position on an inversion centre. The Si-CH(2)-C(ipso) plane is approximately orthogonal to the plane of the pyridine rings, the corresponding dihedral angle being 82.0?(2)°.

| S-EPMC2960436 | biostudies-literature

Solid-State Emissive Aroyl-S,N-Ketene Acetals with Tunable Aggregation-Induced Emission Characteristics.

Project description:N-Benzyl aroyl-S,N-ketene acetals can be readily synthesized by condensation of aroyl chlorides and N-benzyl 2-methyl benzothiazolium salts in good to excellent yields, yielding a library of 35?chromophores with bright solid-state emission and aggregation-induced emission characteristics. Varying the substituent from electron-donating to electron-withdrawing enables the tuning of the solid-state emission color from deep blue to red.

| S-EPMC7317214 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data