Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective Markovnikov Addition of Carbamates to Allylic Alcohols for the Construction of ?-Secondary and ?-Tertiary Amines.

ABSTRACT: Herein we describe the development of a Pd-catalyzed enantioselective Markovnikov addition of carbamates to allylic alcohols for the construction of ?-tertiary and ?-secondary amines. The reaction affords a range of ?-amino alcohols, after reduction of the aldehyde in situ, which contain a variety of functional groups in moderate yields and moderate to good enantioselectivities. These products can be readily oxidized to ?-amino acids, valuable building blocks for the synthesis of biologically active compounds. Mechanistic studies indicate that the C-N bond formation occurs via a syn amino-palladation mechanism, an insight which may guide future reaction development given the limited number of enantioselective syntheses of ?-tertiary amines.

SUBMITTER: Bahamonde A

PROVIDER: S-EPMC6583784 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Catalytic enantioselective epoxidation of tertiary allylic and homoallylic alcohols.

Project description:An efficient and versatile method for the enantioselective epoxidation of both tertiary allylic and homoallylic alcohols catalyzed by Hf(IV)-bishydroxamic acid (BHA) complexes is described. Asymmetric epoxidation, kinetic resolution, and desymmetrization have been developed, demonstrating the flexible nature of the Hf(IV)-BHA system. This is the first report in which these substrates were obtained with enantioselectivities of up to 99%.

| S-EPMC3625140 | biostudies-literature

Direct, intermolecular, enantioselective, iridium-catalyzed allylation of carbamates to form carbamate-protected, branched allylic amines.

Project description:The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylic amines with high regioselectivity and enantioselectivity is reported. This process occurs without base or with 0.5 equiv K(3)PO(4) in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted allylic carbonates with BocNH(2), FmocNH(2), CbzNH(2), TrocNH(2), TeocNH(2), and 2-oxazolidinone occur in good yields, with high selectivity for the branched isomer and high enantioselectivities (98% average ee).

| S-EPMC2740486 | biostudies-literature

Enantioselective dichlorination of allylic alcohols.

Project description:The development of an enantioselective allylic alcohol dichlorination catalyzed by dimeric cinchona alkaloid derivatives and employing aryl iododichlorides as chlorine sources is reported. Reaction optimization, exploration of the substrate scope, and a model for stereoinduction are presented.

| S-EPMC3107004 | biostudies-literature

Simple strategy for synthesis of optically active allylic alcohols and amines by using enantioselective organocatalysis.

Project description:A simple organocatalytic one-pot protocol for the construction of optically active allylic alcohols and amines using readily available reactants and catalyst is presented. The described reaction is enabled by an enantioselective enone epoxidation/aziridination-Wharton-reaction sequence affording two highly privileged and synthetically important classes of compounds in an easy and benign way. The advantages of the described sequence include easy generation of stereogenic allylic centers, also including quaternary stereocenters, with excellent enantio- and diastereomeric-control and high product diversity. Furthermore, using monosubstituted enones as substrates, having moderate enantiomeric excess, the one-pot reaction sequence proceeds with an enantioenrichment of the products and high diastereoselectivity was achieved.

| S-EPMC2996415 | biostudies-literature

Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation.

Project description:The nucleophilic addition of methanol and other alcohols to 1,1-diphenylethylene (1) and styrene (6) into the Markovnikov- and anti-Markovnikov-type products was selectively achieved with 1-(N,N-dimethylamino)pyrene (Py) and 1,7-dicyanoperylene-3,4:9,10-tetracarboxylic acid bisimide (PDI) as photoredox catalysts. The regioselectivity was controlled by the photocatalyst. For the reductive mode towards the Markovnikov-type regioselectivity, Py was applied as photocatalyst and triethylamine as electron shuttle. This approach was also used for intramolecular additions. For the oxidative mode towards the anti-Markovnikov-type regioselectivety, PDI was applied together with Ph-SH as additive. Photocatalytic additions of a variety of alcohols gave the corresponding products in good to excellent yields. The proposed photocatalytic electron transfer mechanism was supported by detection of the PDI radical anion as key intermediate and by comparison of two intramolecular reactions with different electron density. Representative mesoflow reactor experiments allowed to significantly shorten the irradiation times and to use sunlight as "green" light source.

| S-EPMC7877480 | biostudies-literature

Diverse synthesis of α-tertiary amines and tertiary alcohols via desymmetric reduction of malonic esters.

Project description:Amines and alcohols with a fully substituted α-carbon are structures of great value in organic synthesis and drug discovery. While conventional methods towards these motifs often rely on enantioselective carbon-carbon or carbon-heteroatom bond formation reactions, a desymmetric method is developed here by selectively hydrosilylating one of the esters of easily accessible α-substituted α-amino- and -oxymalonic esters. The desymmetrization is enabled by a suite of dinuclear zinc catalysts with pipecolinol-derived tetradentate ligands and can accommodate a diverse panel of heteroatom substituents, including secondary amides, tertiary amines, and ethers of different sizes. The polyfunctionalized reduction products, in return, have provided expeditious approaches to enantioenriched nitrogen- and oxygen-containing molecules, including dipeptides, vitamin analogs, and natural metabolites.

| S-EPMC9376102 | biostudies-literature

Nickel-catalyzed enantioselective allylic alkylation of lactones and lactams with unactivated allylic alcohols.

Project description:The first nickel-catalyzed enantioselective allylic alkylation of lactone and lactam substrates to deliver products bearing an all-carbon quaternary stereocenter is reported. The reaction, which utilizes a commercially available chiral bisphosphine ligand, proceeds in good yield with a high level of enantioselectivity (up to 90% ee) on a range of unactivated allylic alcohols for both lactone and lactam nucleophiles. The utility of this method is further highlighted via a number of synthetically useful product transformations.

| S-EPMC5912103 | biostudies-other

Catalytic Regio- and Enantioselective Haloazidation of Allylic Alcohols.

Project description:Herein we report a highly regio- and stereoselective haloazidation of allylic alcohols. This enantioselective reaction uses readily available materials and can be performed on a variety of alkyl-substituted alkenes and can incorporate either bromine or chlorine as the electrophilic halogen component. Both halide and azido groups of the resulting products can be transformed into valuable building blocks with complete stereospecificity. The first example of an enantioselective 1,4-haloazidation of a conjugated diene is reported as well as its application to a concise synthesis of an aza-sugar.

| S-EPMC6499076 | biostudies-literature

Stereoselective Synthesis of Tertiary Allylic Amines by Titanium-Catalyzed Hydroaminoalkylation of Alkynes with Tertiary Amines.

Project description:Intermolecular hydroaminoalkylation reactions of symmetrical and unsymmetrical alkynes with tertiary amines take place in the presence of catalytic amounts of TiBn4 , Ph3 C[B(C6 F5 )4 ], and a sterically demanding aminopyridinato ligand precursor. The resulting products, synthetically and pharmaceutically useful tertiary β,γ-disubstituted allylic amines, are formed in convincing yields and with excellent stereoselectivity. Particularly promising for future applications is the fact that even the industrial side product trimethylamine can be used as a substrate.

| S-EPMC9303398 | biostudies-literature

Enantioselective synthesis of alpha-tertiary hydroxyaldehydes by palladium-catalyzed asymmetric allylic alkylation of enolates.

Project description: Not available

| S-EPMC2533583 | biostudies-literature