A simple and efficient organocatalytic enantioselective hydrophosphonylation of imines to enantiomerically enriched alpha-amino phosphonates is reported. By using 10 mol % of quinine as the catalyst in the enantioselective addition of diethyl phosphite to N-Boc protected imines, alpha-amino phosphonates are obtained in moderate to good yields and with up to 94% ee.
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http://dx.doi.org/10.1021/jo060708h | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, University of Texas at Austin, Austin 78712, Texas, United States.
J Am Chem Soc
January 2025
Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
Regiodivergent asymmetric synthesis represents a transformative strategy for the efficient generation of structurally diverse chiral products from a single set of starting materials, significantly enriching their enantiomeric composition. However, the design of radical-mediated regiodivergent and enantioselective reactions that can accommodate a wide range of functional groups and substrates has posed significant challenges. The obstacles primarily lie in switching the regioselectivity and achieving high enantiodiscrimination, especially when dealing with high-energy intermediates.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia.
Cyclopropanols have attracted significant attention in organic synthesis as versatile three-carbon synthons, as this readily available class of donor-activated cyclopropanes undergoes miscellaneous transformations, either ring-opening or with retention of the cyclopropane ring. This review summarizes stereoselective and stereoretentive transformations suitable for asymmetric synthesis. The utility of cyclopropanols is discussed for two main strategies: (i) substrate-controlled transformations using enantiomerically enriched cyclopropanol intermediates through a traditional approach, and (ii) the use of nonchiral or racemic cyclopropanols, where asymmetric induction is achieved through a chiral catalyst, representing a direction that has recently emerged.
View Article and Find Full Text PDFNanoscale
December 2024
Université de Strasbourg, CNRS, CMC UMR 7140, F-67000 Strasbourg, France.
Nanosized chiral octahedral M coordination cages were prepared self-assembly of sulfonylcalix[4]arene tetranuclear M(II) clusters (M = Co or Ni) with enantiomerically enriched linkers based on tris(dipyrrinato)cobalt(III) complexes, appended with peripheral carboxylic groups. Two pairs of enantiomers of cages were obtained and unambiguously characterized from a structural point of view, using single crystal X-ray diffraction. Chiral-HPLC was used to evidence the enantiomers.
View Article and Find Full Text PDFAmino Acids
December 2024
Scientific and Production Center "Armbiotechnology" of NAS RA, 14 Gyurjyan Str, 0056, Yerevan, Armenia.
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