Herein we report a Pd-catalyzed asymmetric allenylic alkylation strategy for the direct functionalization of 1H-indoles by employing P-chiral BIBOP-type ligands. The regioselectivity (N1/C3) of this process can be switched efficiently. Using Cs CO at elevated temperatures in MeCN, N1-alkylated indoles bearing axial chirality with a stereocenter non-adjacent (β) to the nitrogen are produced in good yields with high enantioselectivity and complete N1-regioselectivity regardless of the electronic properties and substitution patterns of diverse indoles. Using K CO at room temperature in CH Cl , chiral C3-alkylated indoles can also be obtained. Notably, we introduce a new class of tri-substituted allenylic electrophiles that proceeded through different pathways from di-substituted allenylic electrophiles.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.202300844 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Gold(I)-Catalyzed Nucleophilic Propargylation of Azinium Ions via Hydroxydihydroazine Intermediates.
Chemistry
January 2025
The GlaxoSmithKline Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Jubilee Campus, Triumph Road, Nottingham, NG7 2TU, UK.
The nucleophilic propargylation of azinium ions with a propargylboronate proceeds efficiently under gold(I) catalysis. A range of N-alkylated pyridinium, quinolinium, and pyrazinium ions undergo propargylation with good yields and high regioselectivities to give various functionalized 1,4-dihydropyridines, 1,2-dihydropyridines, 1,4-dihydroquinolines, 1,2-dihydroquinolines, and 4,5-dihydropyrazines. No allenylation side-products are observed.
View Article and Find Full Text PDFIridium-Catalyzed Enantioselective Vinylogous and Bisvinylogous Allenylic Substitution.
JACS Au
November 2024
Department of Organic Chemistry, Indian Institute of Science, Bangalore560012, India.
Compared to the widely explored enol silanes, the applicability of their extended variants especially as bisvinylogous nucleophiles in enantioselective catalysis has been sparse. Herein, we describe the first enantioselective vinylogous and bisvinylogous allenylic substitution using silyl dienol and trienol ethers, respectively, as a nucleophile. With racemic allenylic alcohols as the electrophile, these enantioconvergent reactions are cooperatively catalyzed by an Ir(I)/(phosphoramidite,olefin) complex and Lewis acidic La(OTf) and display remarkable regio- and diastereoselectivity in most cases.
View Article and Find Full Text PDFAxially chiral α-boryl-homoallenyl boronic esters as versatile toolbox for accessing centrally and axially chiral molecules.
Nat Commun
October 2024
Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
Axially chiral allenes bearing organoboron groups are highly sought-after building blocks in organic synthesis due to their potential for generating a wide range of axially and centrally chiral molecules. However, the existing methods for preparing axially chiral allenes containing boron group are primarily limited to the synthesis of allenyl boronic esters, and strategies for accessing axially chiral homoallenyl boronic esters are still scarce. Here, we report the general method for synthesizing axially chiral α-boryl-homoallenyl boronic esters through a highly regio- and stereoselective copper-mediated S2'-addition of newly prepared (diborylalkyl)copper species to chiral propargyl electrophiles.
View Article and Find Full Text PDFNickel-Catalyzed Photoredox Allenylation of Alkyl Halides.
Org Lett
November 2024
Universite Claude Bernard Lyon 1, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, UMR 5246 du CNRS. 1, rue Victor Grignard, 69100 Villeurbanne, France.
We report a dual Ni/photoredox-catalyzed cross-coupling method for propargyl carbonates and nonactivated alkyl bromides, facilitating the synthesis of a variety of substituted allenes under mild and practical conditions. Mechanistically, the reaction integrates Ni-catalyzed activation of the propargyl electrophile via S' oxidative addition at Ni(I) with silyl radical-induced activation of the alkyl halide through halogen-atom transfer. This methodology provides a gentle approach for introducing allenyl groups into complex halogenated aliphatic molecules, offering further opportunities for derivatization.
View Article and Find Full Text PDFSite-Selective Gold-Catalyzed Alkylation of α-Aminotropones with Allenes.
Org Lett
November 2024
Dipartimento di Chimica "Giacomo Ciamician", Alma Mater Studiorum-Università di Bologna, via P. Gobetti 85, 40129 Bologna, Italy.
The site-selective alkylation of α-aminotropones is effectively realized via gold(I)-catalyzed electrophilic activation of allenamides and allenyl ethers, yielding up to 85% in 30 examples. A dedicated and combined spectroscopic and computational investigation accounts for both chemo- and regioselective profiles of the protocol. New opportunities in the chemical space of tropone/tropolone derivatives are identified.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!