Asymmetric cross-electrophile difunctionalization of tethered alkenes has become a powerful tool for the production of chiral cyclic scaffolds; however, the current studies all focus on carbocyclization reactions. Herein, we report an -cyclization-alkylation reaction and thus showcase the potential of heterocyclization for accessing new enantioenriched cyclic architectures. This work establishes a new approach for enantioselective aza-Heck cyclization/cross-coupling sequence, which remains a long-standing unsolved challenge for the synthetic community. The reaction proceeds with primary, secondary, and a few tertiary alkyl iodides, and the use of newly defined ligands gave highly enantioenriched pyrrolines with improved molecular diversity under mild conditions. The presence of imine functionality allows for further structural variations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jacs.2c05523 | DOI Listing |
Org Biomol Chem
May 2021
Department of Chemistry, University of West Florida, 11000 University Pkway, Pensacola, Fl 32514, USA.
In this study, a new environmentally benign iodine-mediated one-pot iodocyclization/alkylation strategy for the synthesis of benzo[b]thiophene derivatives starting from 2-alkynylthioanisoles was developed. The synthesis of a diverse population of 2,3-disubstituted benzo[b]thiophenes was achieved in high yields by employing moderate reaction conditions using 1,3-dicarbonyl substrates as the nucleophile and various substituted propargyl alcohols as both the cyclization precursor and the alkylating agent. This method resulted in the formation of a series of complex structures obtained in a single step.
View Article and Find Full Text PDFJ Org Chem
October 2019
Department of Chemistry , University of Science and Technology of China, Hefei 230026 , China.
A Pd(II)-catalyzed mild and highly regioselective 6- cyclization/alkylation reaction of -(alkynyl)styrenes with simple allylic alcohols has been developed. Under mild reaction conditions, the vinyl palladium species generated in situ after cyclization could insert a C-C double bond of allylic alcohol through a cross-coupling reaction and led to the formation of (alkyl)naphthalenes. This cascade cross-coupling reaction represents a direct and atom economic method for the construction of functionalized naphthalene derivatives in moderate to good yields.
View Article and Find Full Text PDFJ Org Chem
November 2018
Department of Chemistry , University of Science and Technology of China, Hefei 230026 , China.
The Pd(II)-catalyzed one-pot tandem cyclization/alkylation reactions of enynoates with allylic alcohols have been demonstrated. In this reaction, an innovative protocol proceeded well through Pd-catalyzed intramolecular selective 6- endo cyclization, insertion of allylic alcohols into the Pd-C bond of vinylpalladium species generated in situ, and β-hydrogen elimination processes. This conversion provides a convenient and efficient methodology for the synthesis of 2-alkanone pyrones in moderate to good yields.
View Article and Find Full Text PDFOrg Biomol Chem
May 2012
Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
A practical and efficient protocol for the one-pot synthesis of 2,3-substituted indoles was developed via a palladacycle catalyzed domino cyclization-alkylation reaction involving 2-alkynylanilines and allylic alcohols under mild conditions without any additives.
View Article and Find Full Text PDFChemistry
August 2011
Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany.
This comprehensive study describes our results of samarium diiodide induced 5-exo-trig to 8-exo-trig cyclization/alkylation sequences of 3'-acceptor-substituted indolyl ketones. All cyclization precursors were easily prepared by simple N-alkylation or N-acylation of indole derivatives with the corresponding iodo alkanones, acid chlorides, or lactones. After treatment of indolyl ketones with two equivalents of SmI(2), the generated stabilized carbanionic intermediates were trapped with different electrophiles leading to a variety of highly substituted indoline derivatives in good to very good yields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!