Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Anion-catalyzed addition of gamma-silylallenyl esters to aldehydes: a new entry into [3.2.1] bicyclic natural products.

ABSTRACT: A significant improvement in the generality and reactivity of MBH-type reactions is made possible by anion catalysis and a 1,3-Brook rearrangement. In this new reaction, both aliphatic and aromatic aldehydes are rapidly added to silylallenes, leading to gamma-carbinol allenoates at low temperatures. The utility of these reaction products is demonstrated by a fast-tracked synthesis of a [3.2.1] bisoxa bicycle that makes up the framework of many biologically active natural products, including vitisinol D, an antithrombotic agent.

SUBMITTER: Maity P

PROVIDER: S-EPMC2674362 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Anion-catalyzed addition of gamma-silylallenyl esters to aldehydes: a new entry into [3.2.1] bicyclic natural products.

Maity Pradip P Lepore Salvatore D SD

Journal of the American Chemical Society 20090401 12

A significant improvement in the generality and reactivity of MBH-type reactions is made possible by anion catalysis and a 1,3-Brook rearrangement. In this new reaction, both aliphatic and aromatic aldehydes are rapidly added to silylallenes, leading to gamma-carbinol allenoates at low temperatures. The utility of these reaction products is demonstrated by a fast-tracked synthesis of a [3.2.1] bisoxa bicycle that makes up the framework of many biologically active natural products, including viti ...[more]

PMID: 19271702

Similar Datasets

N-heterocyclic carbene-catalyzed oxidation of unactivated aldehydes to esters.

Project description:N-Heterocyclic carbenes catalyze the oxidation of unactivated aldehydes to esters with manganese(IV) oxide in excellent yield. The reaction proceeds through a transient activated alcohol, which when generated in situ allows for the selective oxidation of the aldehyde under mild conditions. These conditions successfully oxidize potentially epimerizable aldehydes and alcohols while preserving stereochemical integrity. A variety of ester derivatives can be synthesized with variation of the acylated alcohol as well as the unactivated aldehyde.

| S-EPMC2657179 | biostudies-literature

Enantioselective ProPhenol-catalyzed addition of 1,3-diynes to aldehydes to generate synthetically versatile building blocks and diyne natural products.

Project description:A highly enantioselective method for the catalytic addition of terminal 1,3-diynes to aldehydes was developed using our dinuclear zinc ProPhenol (1) system. Furthermore, triphenylphosphine oxide was found to interact synergistically with the catalyst to substantially enhance the chiral recognition. The generality of this catalytic transformation was demonstrated with aryl, alpha,beta-unsaturated and saturated aldehydes, of which the latter were previously limited in alkynyl zinc additions. The chiral diynol products are also versatile building blocks that can be readily elaborated; this was illustrated through highly selective trans-hydrosilylations, which enabled the synthesis of a beta-hydroxyketone and enyne. Additionally, the development of this method allowed for the rapid total syntheses of several biologically important diynol-containing natural products.

| S-EPMC2864593 | biostudies-literature

Synthesis of Bicyclic Hemiacetals Catalyzed by Unnatural Densely Substituted γ-Dipeptides.

Project description:The asymmetric synthesis of bicyclic highly substituted tetrahydropyrans is described. The reaction is catalyzed by unnatural γ-dipeptides based on densely substituted l- and d-proline derivatives. This organocatalytic one-pot reaction takes place among a ketone, a nitroalkene, and an aldehyde to yield an octahydro-2H-chromene scaffold. Monomeric species, from which the corresponding γ-dipeptides are synthesized, cannot catalyze the reaction, thus confirming the emergent nature of the catalytic behavior of these dimeric species.

| S-EPMC9639056 | biostudies-literature

Unconventional Bifunctional Lewis-Bronsted Acid Activation Mode in Bicyclic Guanidine-Catalyzed Conjugate Addition Reactions.

Project description:DFT calculations have demonstrated that the unconventional bifunctional Brønsted-Lewis acid activation mode is generally applicable to a range of nucleophilic conjugate additions catalyzed by bicyclic guanidine catalysts. It competes readily with the conventional bifunctional Brønsted acid mode of activation. The optimal pro-nucleophiles for this unconventional bifunctional activation are acidic substrates with low pKa, while the best electrophiles are flexible 1,4-diamide and 1,4-diester conjugated systems.

| S-EPMC6331857 | biostudies-other

Nickel-catalyzed dehydrogenative cross-coupling: direct transformation of aldehydes into esters and amides.

Project description:By exploring a new mode of nickel-catalyzed cross-coupling, a method to directly transform both aromatic and aliphatic aldehydes into either esters or amides has been developed. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either ?,?,?-trifluoroacetophenone or excess aldehyde. Mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C-H bond is also presented.

| S-EPMC4551080 | biostudies-literature

Peptide-Catalyzed Stereoselective Conjugate Addition Reaction of Aldehydes to C-Substituted Maleimides.

Project description:Catalytic stereoselective additions with maleimides are useful one-step reactions to yield chiral succinimides, molecules that are widespread among therapeutically active compounds but challenging to prepare when the maleimide is C-substituted. We present the tripeptide H-Pro-Pro-Asp-NHC12 H25 as a catalyst for conjugate addition reactions between aldehydes and C-substituted maleimides to form succinimides with three contiguous stereogenic centers in high yields and stereoselectivities. The peptidic catalyst is so chemoselective that no protecting group is needed at the imide nitrogen of the maleimides. Derivatization of the succinimides was straightforward and provided access to chiral pyrrolidines, lactones, and lactams. Kinetic studies, including a Hammett plot, provided detailed insight into the reaction mechanism.

| S-EPMC9306895 | biostudies-literature

Tandem Aldol Condensation - Platinacycle-Catalyzed Addition Reactions of Aldehydes, Methyl Ketones and Arylboronic Acids.

Project description:Tandem aldol condensation of aldehydes with methyl ketones followed by anionic four-electron donor-based (Type I) platinacycle-catalyzed addition reactions of arylboronic acids to form ?-arylated ketones is described. Good to excellent yields of ?-arylated ketones were obtained for the tandem reactions of aromatic/aliphatic aldehydes, methyl ketones and arylboronic acids, and moderate yields were observed for the tandem reaction with ?, ?-unsaturated aldehydes as the aldehyde source.

| S-EPMC3547403 | biostudies-other

New Bicyclic Azalide Macrolides Obtained by Tandem Palladium Catalyzed Allylic Alkylation/Conjugated Addition Reaction.

Project description:Unprecedented tandem allylic alkylation/intermolecular Michael addition was used in the preparation of novel bicyclic azalides. NMR spectroscopy was used not only to unambiguously determine and characterize the structures of these unexpected products of chemical reaction but also to investigate the effect the rigid bicyclic modification has on the conformation of the whole molecule. Thus, some of the macrolides prepared showed antibacterial activity in the range of well-known antibiotic drug azithromycin.

| S-EPMC8781410 | biostudies-literature

Nickel-Catalyzed Addition of Aryl Bromides to Aldehydes To Form Hindered Secondary Alcohols.

Project description:Transition-metal-catalyzed addition of aryl halides across carbonyls remains poorly developed, especially for aliphatic aldehydes and hindered substrate combinations. We report here that simple nickel complexes of bipyridine and PyBox can catalyze the addition of aryl halides to both aromatic and aliphatic aldehydes using zinc metal as the reducing agent. This convenient approach tolerates acidic functional groups that are not compatible with Grignard reactions, yet sterically hindered substrates still couple in high yield (33 examples, 70% average yield). Mechanistic studies show that an arylnickel, and not an arylzinc, adds efficiently to cyclohexanecarboxaldehyde, but only in the presence of a Lewis acid co-catalyst (ZnBr2).

| S-EPMC6368192 | biostudies-literature

Enantioselective Aldol Addition of Acetaldehyde to Aromatic Aldehydes Catalyzed by Proline-Based Carboligases.

Project description:Aromatic ?-hydroxyaldehydes, 1,3-diols, and ?,?-unsaturated aldehydes are valuable precursors to biologically active natural products and drug molecules. Herein we report the biocatalytic aldol condensation of acetaldehyde with various aromatic aldehydes to give a number of aromatic ?,?-unsaturated aldehydes using a previously engineered variant of 4-oxalocrotonate tautomerase [4-OT(M45T/F50A)] as carboligase. Moreover, an efficient one-pot two-step chemoenzymatic route toward chiral aromatic 1,3-diols has been developed. This one-pot chemoenzymatic strategy successfully combined a highly enantioselective aldol addition step catalyzed by a proline-based carboligase [4-OT(M45T/F50A) or TAUT015] with a chemical reduction step to convert enzymatically prepared aromatic ?-hydroxyaldehydes into the corresponding 1,3-diols with high optical purity (e.r. up to >99:1) and in good isolated yield (51-92%). These developed (chemo)enzymatic methodologies offer alternative synthetic choices to prepare a variety of important drug precursors.

| S-EPMC7045556 | 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