The hetisine-type natural products exhibit one of the most complex carbon skeletons within the diterpenoid alkaloid family. The use of network analysis has enabled a synthesis strategy to access alkaloids in this class with hydroxylation on the A-ring. Key transformations include a benzyne acyl-alkylation to construct a key fused 6-7-6 tricycle, a chemoselective nitrile reduction, and sequential C-N bond formations using a reductive cyclization and a photochemical hydroamination to construct an embedded azabicycle. Our strategy should enable access to myriad natural and unnatural products within the hetisine-type.
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http://dx.doi.org/10.1021/jacs.8b05043 | DOI Listing |
Org Biomol Chem
July 2024
Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata-700009, India.
Distinct protocols have been devised for the preparation of hybrid heterocyclic scaffolds like π-extended pyrido-acridines and quinazolino-phenanthridines duly materialized through Rh(III)- and Pd(II)-mediated catalytic courses commencing from acridine and quinazolimine scaffolds. Interestingly, the parent compounds (acridines and quinazolimines) are actualized from 2-aminobenzonitrile and anthranilic acid, where 2-aminobenzonitrile acts as the 1,4-dipolarophilic species and anthranilic acid as the benzyne precursor. The molecular assembly of acridine suggests the participation of two benzyne units.
View Article and Find Full Text PDFChemistry
August 2024
Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Chemistry, IGCME, Sun Yat-sen University, 510275, Guangzhou, Guangdong, China.
Benzyne derived from hexadehydrogenated Diels Alder (HDDA) reactions was found to be an efficient hydrosilylation acceptors. Various silanes can react smoothly with HDDA-derived benzyne to give the arylation products. Lewis acid such as boron trifluoride etherate can accelerate these hydrosilylation reactions.
View Article and Find Full Text PDFJ Org Chem
July 2023
Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
Ortho-benzyne and 1,2-azaborinine are related by the formal exchange of the CC triple bond by the isoelectronic BN unit. The (2 + 2) and (2 + 4) cycloaddition reactions of 1,2-azaborinine with the different organic π systems (ethene, ethyne, 1,3-butadiene, 1,3-cyclopentadiene, furan, benzene) were examined computationally using density functional, second-order perturbation, and coupled-cluster methods. All reactions of 1,2-azaborinine with the studied substrates are highly exothermic and involve the formation of Lewis acid-base complexes of 1,2-azaborinine and respective π systems.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2023
State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Exploration of elementary reactions in organometallic catalysis is an important method with which to discover new reactions. In this article, we report a gold(I)-catalyzed iodo-alkynylation of benzyne involving the merging of challenging migratory insertion and an oxidative addition process in gold catalytic cycle. A wide range of structurally diverse alkynyl iodides are good coupling partners in this iodo-alkynylation transformation.
View Article and Find Full Text PDFNature
June 2023
Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA.
Since 1825, compounds with the molecular formula CH-most notably benzene-have been the subject of rigorous scientific investigation. Of these compounds, 1,2,3-cyclohexatriene has been largely overlooked. This strained isomer is substantially (approximately 100 kcal mol) higher in energy compared with benzene and, similar to its relatives benzyne and 1,2-cyclohexadiene, should undergo strain-promoted reactions.
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