Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric synthesis of dibenzo[b,d]azepines by Cu-catalyzed reductive or borylative cyclization.

ABSTRACT: A copper-catalyzed asymmetric intramolecular reductive cyclization for the synthesis of dibenzo[b,d]azepines is described. Use of 2'-vinyl-biaryl-2-imines as substrates and in situ formed [Cu^I/(Ph-BPE)] as the catalyst enables the synthesis of 7-membered bridged biarylamines containing both central and axial stereogenic elements in high yields (up to 98%) and with excellent diastereo- and enantioselectivities (>20 : 1 d.r., up to 99% ee). Moreover, the same catalyst was found to facilitate a related borylative cyclization to afford versatile boronic ester derivatives. Both reactions proceed under mild conditions (rt) and are applicable to a variety of substituted aromatic and heterocyclic derivatives.

SUBMITTER: Rodriguez-Salamanca P

PROVIDER: S-EPMC8635211 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric synthesis of dibenzo[b,d]azepines by Cu-catalyzed reductive or borylative cyclization.

Rodríguez-Salamanca Patricia P Martín-de la Calle Rocío R Rodríguez Verónica V Merino Pedro P Fernández Rosario R Lassaletta José M JM Hornillos Valentín V

Chemical science 20211110 46

A copper-catalyzed asymmetric intramolecular reductive cyclization for the synthesis of dibenzo[b,d]azepines is described. Use of 2'-vinyl-biaryl-2-imines as substrates and in situ formed [CuI/(Ph-BPE)] as the catalyst enables the synthesis of 7-membered bridged biarylamines containing both central and axial stereogenic elements in high yields (up to 98%) and with excellent diastereo- and enantioselectivities (>20 : 1 d.r., up to 99% ee). Moreover, the same cataly ...[more]

PMID: 34976349

Similar Datasets

Synthesis of Functionalized Azepines via Cu(I)-Catalyzed Tandem Amination/Cyclization Reaction of Fluorinated Allenynes.

Project description:An efficient method for the selective preparation of trifluoromethyl-substituted azepin-2-carboxylates and their phosphorous analogues has been developed via Cu(I)-catalyzed tandem amination/cyclization reaction of functionalized allenynes with primary and secondary amines.

| S-EPMC9416787 | biostudies-literature

Enantio- and Diastereoselective Synthesis of Functionalized Carbocycles by Cu-Catalyzed Borylative Cyclization of Alkynes with Ketones.

Project description:A single-pot Cu-catalyzed enantio- and diastereoselective tandem hydroboration/borylative cyclization of alkynes with ketones for the synthesis of carbocycles is reported. The reaction proceeds via desymmetrization and generates four contiguous stereocenters, including an all-carbon quaternary center. The method provides rapid access to [6,5]- and [5,5]-bicycles and cyclopentane products. Catalyst-controlled diastereoselectivity by selection of bisphosphine ligand is noted. Utility of the products is demonstrated by site- and chemoselective transformations that afford valuable alkenyl and allyl organoborons.

| S-EPMC6702961 | biostudies-literature

Enantioselective Copper-Catalyzed Borylative Cyclization for the Synthesis of Quinazolinones.

Project description:Quinazolinones are common substructures in molecules of medicinal importance. We report an enantioselective copper-catalyzed borylative cyclization for the assembly of privileged pyrroloquinazolinone motifs. The reaction proceeds with high enantio- and diastereocontrol, and can deliver products containing quaternary stereocenters. The utility of the products is demonstrated through further manipulations.

| S-EPMC8252434 | biostudies-literature

Intramolecular asymmetric reductive amination: synthesis of enantioenriched dibenz[c,e]azepines.

Project description:An Ir-catalyzed intramolecular asymmetric reductive amination (ARA) of bridged biaryl derivatives has been described. Using this unprecedented approach, synthetically useful dibenz[c,e]azepines containing both central and axial chiralities are obtained with excellent enantiocontrol (up to 97% ee). This methodology represents a rare example of enantioselective chemocatalytic synthesis of chiral dibenz[c,e]azepines featuring a broad substrate scope, and their synthetic utilities are exhibited by derivatizing the products into a chiral amino acid derivative and chiral phosphoramidite ligands, which display excellent enantiocontrol in Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid derivatives. Remarkably, our method is also applicable to enantioselectively synthesize an allocolchicine analogue.

| S-EPMC6385856 | biostudies-literature

Enantioselective Cu(I)-catalyzed borylative cyclization of enone-tethered cyclohexadienones and mechanistic insights.

Project description:The catalytic asymmetric borylation of conjugated carbonyls followed by stereoselective intramolecular cascade cyclizations with in situ generated chiral enolates are extremely rare. Herein, we report the enantioselective Cu(I)-catalyzed β-borylation/Michael addition on prochiral enone-tethered 2,5-cyclohexadienones. This asymmetric desymmetrization strategy has a broad range of substrate scope to generate densely functionalized bicyclic enones bearing four contiguous stereocenters with excellent yield, enantioselectivity, and diastereoselectivity. One-pot borylation/cyclization/oxidation via the sequential addition of sodium perborate reagent affords the corresponding alcohols without affecting yield and enantioselectivity. The synthetic potential of this reaction is explored through gram-scale reactions and further chemoselective transformations on products. DFT calculations explain the requirement of the base in an equimolar ratio in the reaction, as it leads to the formation of a lithium-enolate complex to undergo C-C bond formation via a chair-like transition state, with a barrier that is 22.5 kcal/mol more favourable than that of the copper-enolate complex.

| S-EPMC8844005 | biostudies-literature

Asymmetric Synthesis of Flavanols via Cu-Catalyzed Kinetic Resolution of Chromenes and Their Anti-Inflammatory Activity

Project description:We report a highly efficient kinetic resolution of chromenes for the first time via a Cu-catalyzed asymmetric hydroboration. This novel approach features simple one-pot synthesis of chiral flavan-3-ols containing two vicinal stereogenic centers via a highly efficient kinetic resolution pathway (s factor up to 1060, >99% ee for most substrates and products, exclusively trans products). In addition, the anti-inflammation effects of these diversified flavan-3-ols have been further studied by the in vitro experiments and RNA-sequencing (RNA-seq) analysis. The modified flavan-3-ol natural product derivatives showed inhibitory effects on the expression and secretion of pro-inflammation cytokines including IL-1β, IL-6 and TNF-α, as well as inhibiting the inflammation responses through downregulating the gene transcriptions closely related to IL-17 signaling pathway, PI3K-Akt signaling pathway and TNF signaling pathway, which suggest these newly synthesized compounds are potent lead compounds for treating inflammation diseases.

2021-07-30 | GSE181052 | GEO

Iridium-catalyzed reductive nitro-Mannich cyclization.

Project description:A new chemoselective reductive nitro-Mannich cyclization reaction sequence of nitroalkyl-tethered lactams has been developed. Relying on the rapid and chemoselective iridium(I)-catalyzed reduction of lactams to the corresponding enamine, subsequent nitro-Mannich cyclization of tethered nitroalkyl functionality provides direct access to important alkaloid natural-product-like structures in yields up to 81 % and in diastereoselectivities that are typically good to excellent. An in-depth understanding of the reaction mechanism has been gained through NMR studies and characterization of reaction intermediates. The new methodology has been applied to the total synthesis of (±)-epi-epiquinamide in four steps.

| S-EPMC4730865 | biostudies-literature

Synthesis of BN-Polyarenes by a Mild Borylative Cyclization Cascade.

Project description:Reaction of BCl3 with suitably substituted o-alkynylanilines promotes a cascade reaction in which BN-polycyclic compounds are obtained via the formation of two new cycles and three new bonds in a single operational step. The reaction is highly efficient and takes place at room temperature, providing a very mild and straightforward strategy for the preparation of BN-aromatic compounds, which can be further transformed into a variety of BN-PAHs with different polycyclic cores and substituents.

| S-EPMC9384698 | biostudies-literature

Synthesis of indolines via a domino Cu-catalyzed amidation/cyclization reaction.

Project description:A highly efficient one-pot procedure for the synthesis of indolines and their homologues based on a domino Cu-catalyzed amidation/nucleophilic substitution reaction has been developed. Substituted 2-iodophenethyl mesylates and related compounds afforded the corresponding products in excellent yields. No erosion of optical purity was observed when transforming enantiomerically pure mesylates under the reaction conditions.

| S-EPMC2489202 | biostudies-literature

Asymmetric synthesis of primary amines catalyzed by thermotolerant fungal reductive aminases.

Project description:Chiral primary amines are important intermediates in the synthesis of pharmaceutical compounds. Fungal reductive aminases (RedAms) are NADPH-dependent dehydrogenases that catalyse reductive amination of a range of ketones with short-chain primary amines supplied in an equimolar ratio to give corresponding secondary amines. Herein we describe structural and biochemical characterisation as well as synthetic applications of two RedAms from Neosartorya spp. (NfRedAm and NfisRedAm) that display a distinctive activity amongst fungal RedAms, namely a superior ability to use ammonia as the amine partner. Using these enzymes, we demonstrate the synthesis of a broad range of primary amines, with conversions up to >97% and excellent enantiomeric excess. Temperature dependent studies showed that these homologues also possess greater thermal stability compared to other enzymes within this family. Their synthetic applicability is further demonstrated by the production of several primary and secondary amines with turnover numbers (TN) up to 14 000 as well as continous flow reactions, obtaining chiral amines such as (R)-2-aminohexane in space time yields up to 8.1 g L-1 h-1. The remarkable features of NfRedAm and NfisRedAm highlight their potential for wider synthetic application as well as expanding the biocatalytic toolbox available for chiral amine synthesis.

| S-EPMC8159254 | biostudies-literature