Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Catalyst-Controlled 1,2- and 1,1-Arylboration of ?-Alkyl Alkenyl Arenes.

ABSTRACT: Two methods are reported for the 1,2- and 1,1-arylboration of ?-methyl vinyl arenes. In the case of 1,2-arylboration, the formation of a quaternary center occurred through a rare cross-coupling reaction of a tertiary organometallic complex. 1,1-Arylboration was enabled by catalyst optimization and occurred through a ?-hydride elimination/reinsertion cascade. Enantioselective variants of both processes are presented as well as mechanistic investigations.

SUBMITTER: Bergmann AM

PROVIDER: S-EPMC6823597 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Catalyst-Controlled 1,2- and 1,1-Arylboration of α-Alkyl Alkenyl Arenes.

Bergmann Allison M AM Dorn Stanna K SK Smith Kevin B KB Logan Kaitlyn M KM Brown M Kevin MK

Angewandte Chemie (International ed. in English) 20190109 6

Two methods are reported for the 1,2- and 1,1-arylboration of α-methyl vinyl arenes. In the case of 1,2-arylboration, the formation of a quaternary center occurred through a rare cross-coupling reaction of a tertiary organometallic complex. 1,1-Arylboration was enabled by catalyst optimization and occurred through a β-hydride elimination/reinsertion cascade. Enantioselective variants of both processes are presented as well as mechanistic investigations. ...[more]

PMID: 30521697

Similar Datasets

Catalyst Controlled Regiodivergent Arylboration of Dienes.

Project description:A method for the regiodivergent arylboration of dienes is presented. These reactions allow for the formation of a diverse range of synthetically versatile products from simple precursors. Through mechanistic studies, these reactions likely operate by initial addition of a Cu-Bpin complex across the diene followed by Pd-catalyzed cross coupling with an aryl halide or pseudohalide.

| S-EPMC5618444 | biostudies-literature

Silver-catalyzed regioselective deuteration of (hetero)arenes and α-deuteration of 2-alkyl azaarenes.

Project description:A simple silver-catalyzed regioselective deuteration of (hetero)arenes and α-deuteration of 2-alkyl azaarenes has been described. This strategy provides an efficient and practical avenue to access various deuterated electron-rich arenes, azaarenes and α-deuterated 2-alkyl azaarenes with good to excellent deuterium incorporation utilizing D2O as the source of deuterium atoms.

| S-EPMC9055237 | biostudies-literature

Rh-catalyzed intermolecular cyclopropanation with alpha-alkyl-alpha-diazoesters: catalyst-dependent chemo- and diastereoselectivity.

Project description:A Rh-catalyzed procedure for the cyclopropanation of alkenes with alpha-alkyl-alpha-diazoesters is described. With dirhodium tetraoctanoate, the predominant pathway is beta-hydride elimination. While a number of sterically demanding carboxylate ligands serve to avoid beta-hydride elimination, it was found that triphenylacetate (TPA) also imparts high diastereoselectivity.

| S-EPMC2696156 | biostudies-literature

Expanding the functional group tolerance of cross-coupling in 1,2-dihydro-1,2-azaborines: installation of alkyl, alkenyl, aryl, and heteroaryl substituents while maintaining a B-H bond.

Project description:Palladium-catalyzed Negishi cross-coupling of 3-bromo-1-(tert-butyldimethylsilyl)-1,2-dihydro-1,2-azaborine while maintaining the B-H functionality has been demonstrated. 17 examples, including dialkylzinc, alkyl-, alkenyl-, aryl-, as well as nitrogen-, sulfur-, and oxygen-containing heteroaryl-zinc halide reagents have been coupled to generate new C(3) substituted 1,2-azaborines in moderate to excellent yields.

| S-EPMC6752210 | biostudies-literature

Alkene 1,2-Difunctionalization by Radical Alkenyl Migration.

Project description:Transition-metal-free radical ?-perfluoroalkylation with the accompanying vicinal ?-alkenylation of unactivated alkenes is presented. These radical cascades proceed by means of 1,4- or 1,5-alkenyl migration by electron catalysis on readily accessed allylic alcohols. The reactions comprise a regioselective perfluoroalkyl radical addition with subsequent alkenyl migration and concomitant deprotonation to generate a ketyl radical anion that sustains the chain as a single-electron-transfer reducing reagent.

| S-EPMC5838557 | biostudies-other

Catalyst-controlled doubly enantioconvergent coupling of racemic alkyl nucleophiles and electrophiles.

Project description:Stereochemical control in the construction of carbon-carbon bonds between an alkyl electrophile and an alkyl nucleophile is a persistent challenge in organic synthesis. Classical substitution reactions via SN1 and SN2 pathways are limited in their ability to generate carbon-carbon bonds (inadequate scope, due to side reactions such as rearrangements and eliminations) and to control stereochemistry when beginning with readily available racemic starting materials (racemic products). Here, we report a chiral nickel catalyst that couples racemic electrophiles (propargylic halides) with racemic nucleophiles (β-zincated amides) to form carbon-carbon bonds in doubly stereoconvergent processes, affording a single stereoisomer of the product from two stereochemical mixtures of reactants.

| S-EPMC7566878 | biostudies-literature

Enantio- and Diastereoselective 1,2-Additions to α-Ketoesters with Diborylmethane and Substituted 1,1-Diborylalkanes.

Project description:The catalytic enantioselective synthesis of boronate-substituted tertiary alcohols through additions of diborylmethane and substituted 1,1-diborylalkanes to α-ketoesters is reported. The reactions are catalyzed by readily available chiral phosphine/copper(I) complexes and produce β-hydroxyboronates containing up to two contiguous stereogenic centers in up to 99:1 e.r. and greater than 20:1 d.r. The utility of the organoboron products is demonstrated through several chemoselective functionalizations. Evidence indicates the reactions occur via an enantioenriched α-boryl-copper-alkyl intermediate.

| S-EPMC5000392 | biostudies-literature

Directed nickel-catalyzed 1,2-dialkylation of alkenyl carbonyl compounds.

Project description:A nickel-catalyzed conjunctive cross-coupling of non-conjugated alkenes, alkyl halides, and alkylzinc reagents is reported. Regioselectivity is controlled by chelation of a removable bidentate 8-aminoquinoline directing group. Under optimized conditions, a wide range of 1,2-dialkylated products can be accessed in moderate to excellent yields. To the best of our knowledge, this report represents the first example of three-component 1,2-dialkylation of non-conjugated alkenes to introduce differentiated alkyl fragments.

| S-EPMC6001383 | biostudies-literature

Directed, nickel-catalyzed 1,2-alkylsulfenylation of alkenyl carbonyl compounds.

Project description:We report a regioselective, nickel-catalyzed syn-1,2-carbosulfenylation of non-conjugated alkenyl carbonyl compounds with alkyl/arylzinc nucleophiles and tailored N-S electrophiles. This method allows the simultaneous installation of a variety of C(sp3) and S(Ar) (or Se(Ar)) groups onto unactivated alkenes, which complements previously developed 1,2-carbosulfenylation methodology in which only C(sp2) nucleophiles are compatible. A bidentate directing auxiliary controls regioselectivity, promotes high syn-stereoselectivity with a variety of E- and Z-internal alkenes, and enables the use of an array of electrophilic sulfenyl (and seleno) electrophiles. Among compatible electrophiles, those with N-alkyl-benzamide leaving groups were found to be especially effective, as determined through comprehensive structure-reactivity mapping.

| S-EPMC9172569 | biostudies-literature

Rh(2)(S-PTTL)(3)TPA-A Mixed Ligand Dirhodium(II) Catalyst for Enantioselective Reactions of α-Alkyl-α-Diazoesters.

Project description:Herein we report the synthesis of the mixed ligand paddlewheel complex dirhodium(II) tris[N-phthaloyl-(S)-tert-leucinate] triphenylacetate, Rh(2)(S-PTTL)(3)TPA, the structure of which bears similarity to the chiral crown complex Rh(2)(S-PTTL)(4). Rh(2)(S-PTTL)(3)TPA engages substrate classes (aliphatic alkynes, silylacetylenes, α-olefins) that are especially challenging in intermolecular reactions of α-alkyl-α-diazoesters, and catalyzes enantioselective cyclopropanation, cyclopropenation, and indole C-H functionalization with yields and enantioselectivities that are comparable or superior to Rh(2)(S-PTTL)(4). Mixing ligands on paddlewheel complexes offers a versatile handle for diversifying catalyst structure and reactivity. The results described herein illustrate how mixed ligand catalysts can create new opportunities for the optimization of catalytic asymmetric processes.

| S-EPMC3486924 | 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