Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Pentapeptide Nanoreactor as a Platform for Halogenations, Diels-Alder Reaction, and Morita-Baylis-Hillman Reaction.

ABSTRACT: A pentapeptide nanoreactor has been designed and synthesized as a platform to carry out the traditional organic reactions such as bromination, iodination, cycloaddition, and condensation reactions. The pentapeptide Boc-Phe-Phe-Aib-Phe-Phe-OMe with a supramolecular helical structure and ?-rich channel provides nanoconfinements and thus facilitates the organic reactions. Bromination and iodination of aniline take place without any halogen carrier (Lewis acid) in the pentapeptide platform. Iodination produced p-iodoaniline only. The Diels-Alder reaction between furan and maleic anhydride increased 2-fold in the pentapeptide platform and the Morita-Baylis-Hillman reaction of benzaldehyde and ethyl acrylate in methanol enhanced 1.5-fold.

SUBMITTER: Debnath M

PROVIDER: S-EPMC6714524 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Pentapeptide Nanoreactor as a Platform for Halogenations, Diels-Alder Reaction, and Morita-Baylis-Hillman Reaction.

Debnath Mintu M Sasmal Supriya S Podder Debasish D Haldar Debasish D

ACS omega 20190813 9

A pentapeptide nanoreactor has been designed and synthesized as a platform to carry out the traditional organic reactions such as bromination, iodination, cycloaddition, and condensation reactions. The pentapeptide Boc-Phe-Phe-Aib-Phe-Phe-OMe with a supramolecular helical structure and π-rich channel provides nanoconfinements and thus facilitates the organic reactions. Bromination and iodination of aniline take place without any halogen carrier (Lewis acid) in the pentapeptide platform. Iodinati ...[more]

PMID: 31497704

Similar Datasets

Morita-Baylis-Hillman reaction of acrylamide with isatin derivatives.

Project description:The Morita-Baylis-Hillman reaction of acrylamide, as an activated alkene, has seen little development due to its low reactivity. We have developed the reaction using isatin derivatives with acrylamide, DABCO as a promoter and phenol as an additive in acetonitrile. The corresponding aza version with acrylate and acrylonitrile has also been developed resulting in high product yields.

| S-EPMC4273229 | biostudies-literature

Application of 7-azaisatins in enantioselective Morita-Baylis-Hillman reaction.

Project description:7-Azaisatin and 7-azaoxindole skeletons are valuable building blocks in diverse biologically active substances. Here 7-azaisatins turned out to be more efficient electrophiles than the analogous isatins in the enantioselective Morita-Baylis-Hillman (MBH) reactions with maleimides using a bifunctional tertiary amine, β-isocupreidine (β-ICD), as the catalyst. This route allows a convenient approach to access multifunctional 3-hydroxy-7-aza-2-oxindoles with high enantiopurity (up to 94% ee). Other types of activated alkenes, such as acrylates and acrolein, could also be efficiently utilized.

| S-EPMC4778495 | biostudies-literature

Expedient Organocatalytic Aza-Morita-Baylis-Hillman Reaction through Ball-Milling.

Project description:A ball-milling enabled tertiary amine catalyzed aza-Morita-Baylis-Hillman reaction is reported. The reaction process does not require solvent, has significantly shorter reaction times than previous methods and is reported on a range of imines and acrylate Michael acceptors across than 26 examples. A 12-fold scaled-up example is also reported as well as experimental comparisons to solution-based experiments and neat-stirred reactions.

| S-EPMC7885690 | biostudies-literature

2-Fluoroenones via an Umpolung Morita-Baylis-Hillman Reaction of Enones.

Project description:Several methods have been reported for the formation of 2-fluoroenones. However, all these methods involve laborious multiple-step sequences with resulting low overall yields. In this paper, we report the first formal enone-α-H to F substitution, leading to 2-fluoroenones in a single step from ubiquitous enones in 63-90% yield. The reaction is applicable to a wide range of aromatic and alkenyl enones and is carried out at room temperature using HF-pyridine complex as the fluoride source. Mechanistic investigations support that the reaction takes place through a rare umpolung Morita-Baylis-Hillman-type mechanism.

| S-EPMC9972470 | biostudies-literature

Engineering an efficient and enantioselective enzyme for the Morita-Baylis-Hillman reaction.

Project description:The combination of computational design and directed evolution could offer a general strategy to create enzymes with new functions. So far, this approach has delivered enzymes for a handful of model reactions. Here we show that new catalytic mechanisms can be engineered into proteins to accelerate more challenging chemical transformations. Evolutionary optimization of a primitive design afforded an efficient and enantioselective enzyme (BH32.14) for the Morita-Baylis-Hillman (MBH) reaction. BH32.14 is suitable for preparative-scale transformations, accepts a broad range of aldehyde and enone coupling partners and is able to promote selective monofunctionalizations of dialdehydes. Crystallographic, biochemical and computational studies reveal that BH32.14 operates via a sophisticated catalytic mechanism comprising a His23 nucleophile paired with a judiciously positioned Arg124. This catalytic arginine shuttles between conformational states to stabilize multiple oxyanion intermediates and serves as a genetically encoded surrogate of privileged bidentate hydrogen-bonding catalysts (for example, thioureas). This study demonstrates that elaborate catalytic devices can be built from scratch to promote demanding multi-step processes not observed in nature.

| S-EPMC7612480 | biostudies-literature

Remarkable influence of microwave heating on Morita-baylis-Hillman reaction in PEG-200.

Project description:BackgroundMorita Baylis Hillman (MBH) reaction is used to introduce carbon-carbon or carbon-heteroatom bond in a molecule. The major drawback of this reaction is the relatively low product yield and long reaction time. Though notable changes have been made to improve the reaction rate and yield of MBH adduct by various groups, a reliable synthetic procedure under ambient temperature in presence moisture and air is remain unsolved. Continuing the effort to improve the rate and yield, we report here an eco-friendly and cost-effective method to generate MBH adducts. Non-volatile polyethylene glycol-200 is used as reusable solvents and the reaction was carried out under the influence of microwave energy.ResultsMicrowave irradiation have a remarkable influence on PEG suspended 4-Diazabicyclo [2.2.2] octane (DABCO) catalysed MBH reaction between aldehydes and ethyl acrylate. Molecular weight of the PEG is found to have a significant influence on the reaction yield. PEG-200 was the most efficient solvent and in combination with DABCO, the medium can be recycled upto three more runs. This reaction condition is successfully applied to obtain MBH adduct of five different aldehydes in very short time with excellent yield and the required catalyst concentration was very low compared to standard MBH reaction. Since the MBH adduct is an important reactive intermediates for many complex organic syntheses, this approach can be successfully utilised as an alternative to existing reaction conditions.ConclusionA new method was developed to improve the reaction rate and yield of MBH reaction The PEG 200-DABCO combination provides a sustainable, non-volatile, recyclable and environment friendly solvent medium to produce MBH adducts. This medium in combination with microwave energy proved to be very effective to introduce a new carbon-carbon or a carbon-heteroatom bond in a molecule.

| S-EPMC3483690 | biostudies-literature

Regioconvergent Nucleophilic Substitutions with Morita-Baylis-Hillman Fluorides.

Project description:Lithium iodide enables regioconvergent C-F bond functionalization of isomeric Morita-Baylis-Hillman fluorides with carbon, sulfur, and nitrogen nucleophiles. The defluorinative carbon-carbon and carbon-heteroatom bond formations give multifunctional compounds in excellent yields and with good to high diastereoselectivities at room temperature. The possibility of catalytic enantioselective allylation is also discussed.

| S-EPMC11301663 | biostudies-literature

Efficient assembly of 2,5,6-substituted pyrimidines via MgI(2)-mediated Morita-Baylis-Hillman reaction.

Project description:A mild and efficient protocol for the synthesis of a 2,6-disubstituted pyrimidine-5-carboxylate library via a Morita-Baylis-Hillman (MBH) adduct is described. Herein, the three step methodology involves the use of substituted alpha-iodomethylene beta-keto ester intermediates obtained after oxidation of the MBH adducts, which are condensed with various types of amidine or guanidine derivatives, to generate the 2, 6-disubstituted pyrimidines-5-carboxylate libraries.

| S-EPMC2919067 | biostudies-literature

Amino acid ionic liquids as catalysts in a solvent-free Morita-Baylis-Hillman reaction.

Project description:In the present work, we describe the preparation of ten amino acid ionic liquids (AAILs) formed from ammonium salts as cations, derivatives of glycerol, and natural amino acids as anions. All of them are viscous oils, colorless or pale yellow, and hygroscopic at room temperature. They have appreciable solubility in many protic and aprotic polar solvents. The AAILs were used as catalysts in a Morita-Baylis-Hillman (MBH) reaction. The ionic liquids derivative from l-proline and l-histidine demonstrated the ability to catalyze the reaction between methyl vinyl ketone and aromatic aldehydes differently substituted in the absence of an additional co-catalyst under organic solvent-free conditions. The AAIL derivatives from l-valine, l-leucine, and l-tyrosine catalyzed the MBH reaction only in the presence of imidazole. The MBH adducts were obtained in moderate to good yields. Although the catalytic site in the ILs was in its enantiomerically pure form, all the MBH adducts were obtained in their racemic form.

| S-EPMC9081752 | biostudies-literature

Computational design of enone-binding proteins with catalytic activity for the Morita-Baylis-Hillman reaction.

Project description:The Morita-Baylis-Hillman reaction forms a carbon-carbon bond between the ?-carbon of a conjugated carbonyl compound and a carbon electrophile. The reaction mechanism involves Michael addition of a nucleophile catalyst at the carbonyl ?-carbon, followed by bond formation with the electrophile and catalyst disassociation to release the product. We used Rosetta to design 48 proteins containing active sites predicted to carry out this mechanism, of which two show catalytic activity by mass spectrometry (MS). Substrate labeling measured by MS and site-directed mutagenesis experiments show that the designed active-site residues are responsible for activity, although rate acceleration over background is modest. To characterize the designed proteins, we developed a fluorescence-based screen for intermediate formation in cell lysates, carried out microsecond molecular dynamics simulations, and solved X-ray crystal structures. These data indicate a partially formed active site and suggest several clear avenues for designing more active catalysts.

| S-EPMC3647451 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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