The first highly enantioselective intermolecular Stetter reaction using simple enones is reported. A series of novel chiral BAC structures were designed and prepared. They were tested in the Stetter reaction with simple aldehydes and enones. The products were generated in excellent yields and enantioselectivities (up to 94% ). Surprisingly, a substoichiometric amount of water was crucial to obtain high enantioselectivities. Chiral BACs were also shown to catalyze 1,6-conjugate addition reactions with paraquinone methides enantioselectively.
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http://dx.doi.org/10.1021/acs.orglett.0c03879 | DOI Listing |
Chem Sci
October 2024
Medicinal Chemistry Theme, Monash Institute of Pharmaceutical Sciences, Monash University Parkville VIC 3052 Australia
The visible-light irradiation of acylsilane tethered vinyl ketones promotes an intramolecular Stetter-type reaction siloxycarbene intermediates. To exploit this unique mode of reactivity, we herein describe the innovative use of acylsilanes as photofunctional directing groups. First, an acylsilane directed ruthenium catalysed C-H olefination reaction was developed to generate benzoylsilanes bearing vinyl ketone functionality.
View Article and Find Full Text PDFChem Commun (Camb)
November 2024
School of Chemistry, University of Edinburgh, Joseph Black Building, King's Buildings, Edinburgh, EH9 3FJ, UK.
Using a protein scaffold covalently functionalised with a thiamine-inspired N-heterocyclic carbene (NHC), we created an artificial Stetterase (ArtiSt) which catalyses a stereoselective, intramolecular Stetter reaction. We demonstrate that ArtiSt functions under ambient conditions with low catalyst loading. Furthermore, activity can be increased >20 fold by altering the protein scaffold.
View Article and Find Full Text PDFPhys Chem Chem Phys
April 2024
Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu City 300, Taiwan.
The intramolecular Stetter reaction catalyzed by a carbene is investigated by density functional theory (DFT) calculations and kinetic simulations. Catalyst 1 first reacts with aldehyde 2 to give the primary adduct (PA). The PA undergoes the intramolecular oxa-Michael reaction to irreversibly generate enol ether intermediate 9.
View Article and Find Full Text PDFOrg Lett
March 2024
Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
Herein we demonstrate a novel organocatalytic method to access multifunctionalized naphthalenes an NHC-catalyzed reaction of ynones and -formyl-tethered Michael acceptors. The presented method proceeds through an intermolecular Stetter reaction-cyclization-aromatization cascade and represents a rare example of organocatalytic benzannulation for the synthesis of substituted arenes by using ynone as a two-carbon synthon. The current method has broad substrate scope; postsynthetic transformations and gram-scale syntheses highlight the practicality of the displayed methodology.
View Article and Find Full Text PDFACS Omega
November 2023
Faculty of Chemistry, Nicolaus Copernicus University in Torun, 7 Gagarin Street, 87-100 Torun, Poland.
An enantioselective synthesis of functionalized -flavanone derivatives using the -heterocyclic carbene-catalyzed intramolecular Stetter reaction of sulphoamido benzaldehydes has been reported. This procedure presents the first original approach for synthesizing chiral functionalized flavonoids at the 3-position, containing an all-carbon quaternary stereogenic center. This advancement significantly enriches the chemical toolbox for the preparation of complex nitrogen-containing compounds and opens up new avenues for further research and development in synthetic organic chemistry.
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