Asymmetric Synthesis of Benzofuranones with a C3 Quaternary Center via an Addition/Cyclization Cascade Using Noncovalent N-Heterocyclic Carbene Catalysis.

Org Lett

School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.

Published: October 2024

An asymmetric addition/cyclization cascade of amidoesters and iminoquinones is developed using noncovalent N-heterocyclic carbene (NHC) catalysis. The process enables access to various functionalized benzofuranones with an all-carbon quaternary stereocenter with high yields and ee values. The reaction displays a broad substrate scope. Via product modifications, enantioenriched synthesis of biologically relevant spirocyclic lactones and lactams is achieved. Substrate activation via noncovalent interaction with NHC is suggested for the process.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.4c03014DOI Listing

Publication Analysis

Top Keywords

addition/cyclization cascade
8
noncovalent n-heterocyclic
8
n-heterocyclic carbene
8
asymmetric synthesis
4
synthesis benzofuranones
4
benzofuranones quaternary
4
quaternary center
4
center addition/cyclization
4
cascade noncovalent
4
carbene catalysis
4

Similar Publications

A visible-light-induced deoxygenative alkylation/cyclization of acrylamides with alcohols activated by CS has been developed by using xanthate salts as alkyl radical precursors in the presence of tricyclohexylphosphine. It proceeds through a tandem radical addition/cyclization process, and this protocol provides a reliable and practical approach to building the skeleton of 3,3-disubstituted oxindoles in moderate to good yields. Notable features of this reaction include readily available starting reagents, broad substrate scope and mild reaction conditions.

View Article and Find Full Text PDF

Photoinduced Ag-Mediated Azaspirocyclic Approach Involves Cyclization and Dearomatization.

J Org Chem

December 2024

State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.

Article Synopsis
  • A new method has been developed for synthesizing azaspirocyclic compounds using visible light, starting from -benzylacrylamides and alkyl chlorooxoacetates.
  • The process involves a series of reactions including free radical addition, cyclization, and dearomatization, allowing for efficient creation of important derivatives and ester groups in one step.
  • This technique shows versatility with various substrates and is able to handle different functional groups effectively, highlighting its efficiency in building complex molecules.
View Article and Find Full Text PDF

Herein, we disclose a cinchona-alkaloid-based squaramide-catalyzed intermolecular oxa-Michael cascade addition cyclization of -protected hydroxyl amine to formyl-tethered Michael acceptors toward the synthesis of enantioenriched 1,2-oxazine scaffolds. Generally, good yield (up to 78%), good to excellent enantiomeric ratio (up to 98:2 er), and excellent regioselectivity (>19:1) were observed. Furthermore, the scalability of this methodology and a successful demonstration of postsynthetic transformations have been accomplished.

View Article and Find Full Text PDF

We disclose herein an efficient and facile method for the synthesis of SF-containing isoquinolinediones with an all-carbon quaternary stereocenter via intramolecular pentafluorosulfanylation of acrylamides using SFCl as a pentafluorosulfanylation reagent. The protocol proceeds under mild reaction conditions and enjoys a broad substrate scope, wide functional group compatibility, and high atom- and step-economy. A radical mechanism involving the SF radical cascade addition/cyclization of acrylamides is proposed.

View Article and Find Full Text PDF

An asymmetric addition/cyclization cascade of amidoesters and iminoquinones is developed using noncovalent N-heterocyclic carbene (NHC) catalysis. The process enables access to various functionalized benzofuranones with an all-carbon quaternary stereocenter with high yields and ee values. The reaction displays a broad substrate scope.

View Article and Find Full Text PDF

Want 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!