The highly regio- and enantioselective molybdenum-catalyzed allylic alkylation reaction has become a powerful synthetic tool during the past few years. This Account describes the achievements gained so far in the area, with special attention directed to the different chiral ligands that have been used for inducing chirality in the products, the range of allylic substrates and nucleophiles employed, mechanistic studies, and applications of the reaction in asymmetric syntheses.
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http://dx.doi.org/10.1021/ar030239v | DOI Listing |
Org Lett
October 2022
Department of Natural Science, Graduate School of Science and Technology, and Research Cluster on "Innovative Chemical Sensing", Tokushima University, Tokushima 770-8506, Japan.
Diastereo- and enantioselective kinetic resolution of racemic planar-chiral 1--2-vinylferrocenes (-) was attained by the molybdenum-catalyzed asymmetric metathesis dimerization (AMD). Two sequential AMD reactions of - (R = Br) provided ()-(,)-1,2-di(2-bromoferrocenyl)ethylene in >99% ee, which was converted to (,)-1,2-bis[(2-diphenylphosphino)ferrocenyl]ethane (,)-. Planar-chiral bisphosphine (,)- coordinated to a dichloropalladium(II) fragment in a -chelating fashion, which was applied as a chiral ligand in the palladium-catalyzed asymmetric allylic alkylation showing enantioselectivity of up to 90% ee.
View Article and Find Full Text PDFJ Am Chem Soc
June 2022
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
The synthesis of enantioenriched molybdenum precatalysts for the asymmetric hydrogenation of substituted quinolines and naphthalenes is described. Three classes of pincer ligands with chiral substituents were evaluated as supporting ligands in the molybdenum-catalyzed hydrogenation reactions, where oxazoline imino(pyridine) chelates were identified as optimal. A series of 2,6-disubstituted quinolines was hydrogenated to enantioenriched decahydroquinolines with high diastereo- and enantioselectivities.
View Article and Find Full Text PDFMolecules
June 2018
Departamento de Química Inorgánica, Universidad de Sevilla, Aptdo. 1203, 41071 Sevilla, Spain.
Chiral alkyl aryl sulfoxides were obtained by molybdenum-catalyzed oxidation of alkyl aryl sulfides with hydrogen peroxide as oxidant in mild conditions with high yields and moderate enantioselectivities. The asymmetry is generated by the use of imidazolium-based dicarboxylic compounds, HL. The in-situ-generated catalyst, a mixture of aqueous [Mo(O)(O₂)₂(H₂O)] with HL as chirality inductors, in the presence of [PPh₄]Br, was identified as the anionic binuclear complex [PPh₄]{[Mo(O)(O₂)₂(H₂O)]₂(μ-L)}, according to spectroscopic data and Density Functional Theory (DFT) calculations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2017
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
The first enantioselective total synthesis of (-)-deoxoapodine is described. Our synthesis of this hexacyclic aspidosperma alkaloid includes an efficient molybdenum-catalyzed enantioselective ring-closing metathesis reaction for the desymmetrization of an advanced intermediate that introduces the C5-quaternary stereocenter. After C21-oxygenation, the pentacyclic core was accessed by electrophilic C19-amide activation and transannular spirocyclization.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
April 2015
Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan).
Winding vine-shaped molecular asymmetry is induced by enantioselective ring-closing metathesis with a chiral molybdenum catalyst. The reaction proceeds under mild conditions through an E-selective ring-closing metathesis leading to macrocyclic bisazoles with enantioselectivities of up to 96% ee.
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