The first highly enantioselective phosphine-catalyzed formal [4+4] annulation has been developed. In the presence of amino-acid-derived phosphines, the unprecedented [4+4] annulations between benzofuran/indole-derived α,β-unsaturated imines and allene ketones proceeded smoothly, thus affording azocines, bearing either a benzofuran or an indole moiety, in excellent yields and with nearly perfect enantioselectivities (≥98 % ee in most cases). This work marks the first efficient asymmetric construction of optically enriched eight-membered rings by phosphine catalysis.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.201707183 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Asymmetric Construction of Chiral 2-Azetines and Axially Chiral Tetrasubstituted Allenes Via Phosphine Catalysis.
Angew Chem Int Ed Engl
November 2024
Department of Chemistry, China Agricultural University, 2 West Yuanmingyuan Road, Beijing, 100193, P. R. China.
Chiral 2-azetines and allenes are highly valuable structural units in natural products and useful chemicals. However, enantioselective synthesis of both 2-azetines and allenes has been extremely challenging. Herein, we present asymmetric construction of chiral 2-azetines (70-98 % yields and up to 96 % ee) through chiral phosphine-catalyzed [2+2] annulation of yne-enones with sulfamate-derived cyclic imines.
View Article and Find Full Text PDFPhosphine-catalyzed enantioselective and diastereodivergent [3+2] cyclization for the construction of oxetane dispirooxindole skeletons.
Chem Commun (Camb)
September 2024
School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China.
We have developed a phosphine catalyzed asymmetric [3+2] cyclization of 3-oxetanone derived MBH carbonates with activated methyleneoxindole, to construct oxetane dispirooxindole skeletons. Diastereodivergent synthesis was realized the control of the phosphine catalyst. The (-)-DIOP provides the diastereoisomers, while the spiro phosphine (R)-SITCP achieves the -epimers.
View Article and Find Full Text PDFEnantioselective Synthesis of Cyclopentanes by Phosphine-Catalyzed β,γ-Annulation of Allenoates.
Org Lett
September 2024
School of Chemistry, Monash University, Clayton 3800, Victoria, Australia.
Article Synopsis
- The study presents a new method for creating cyclopentanes through a phosphine-catalyzed reaction between electron-poor allenes and bifunctional malonates.
- The reaction achieves significant stereoselectivity, producing 23 different cyclopentanes with high enantiomeric ratios (most over 95:5) and good yields.
- Additionally, the research explores a one-pot, three-component approach and a cascade reaction involving annulation and Dieckmann cyclization, along with detailed mechanistic analysis.
Enantioselective phosphine-catalyzed [6 + 1] annulations of α-allyl allenoates with 1,1-bisnucleophiles.
Chem Sci
July 2024
State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University Tianjin 300071 People's Republic of China
Organocatalytic annulations between allenes and bisnucleophiles represent one of the most convenient routes to various carbocycles and heterocycles. However, most examples are limited to the formation of five- and six-membered rings, probably owing to relatively easy handling of short-chained biselectrophiles. Here we report long-chained α-allyl allenoate-derived 1,6-biselectrophiles for the first time, enabling a phosphine catalyzed [6 + 1] annulation with readily available 1,1-bisnucleophilic reagents.
View Article and Find Full Text PDFHighly regio- and stereoselective (3 + 2) annulation reaction of allenoates with 3-methyleneindolin-2-ones catalyzed by a planar chiral [2.2]paracyclophane-based bifunctional phosphine-phenol catalyst.
Org Biomol Chem
October 2024
Laboratory of Medicinal Chemistry, Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya, Aichi 468-8503, Japan.
A planar chiral [2.2]paracyclophane-based phosphine-phenol catalyst catalyzed the (3 + 2) annulation reaction of ethyl 2,3-butadienoate with 3-methyleneindolin-2-ones to produce 2,5-disubstituted cyclopentene-fused C3-spirooxindoles in high yields with high regio-, diastereo-, and enantioselectivities. This catalyst was suitable for reactions of not only benzylideneindolinones but also alkylideneindolinones, the chiral phosphine-catalyzed reactions of which have not yet been reported.
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!