A strategy for the synthesis of differentiated vicinal tertiary diols is described. The key step is a high-yielding, diastereoselective LaCl3·2LiCl-mediated addition of a Grignard or organolithium reagent to ketone 2a. The reaction is believed to proceed via a 1,3-chelated intermediate. One of the adducts has been transformed into a functionalized cyclopentenone resembling the core structure of pactamycin.
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http://dx.doi.org/10.1021/ol4005799 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
We report a Ni-catalyzed vicinal alkylarylation of unactivated alkenes in γ,δ- and δ,ε-alkenylamines with aryl halides and alkylzinc reagents. The reaction is enabled by amine coordination and can use all primary, secondary, and tertiary amines. The reaction constructs two new C(sp)-C(sp) and C(sp)-C(sp) bonds and produces δ- and ε-arylamines with C(sp)-branching at the γ- and δ-positions.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
State Key Laboratory of Chemical Oncogenomics, Institute of Biopharmaceutics and Health Engineering, Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China.
The high percentage of sp-hybridized carbons and the presence of chiral carbon centers could contribute to increased molecular complexity, enhancing the likelihood of clinical success of drug candidates. Three-dimensional (3D) bridged motifs have recently garnered significant interest in medicinal chemistry. Bicyclo[2.
View Article and Find Full Text PDFNat Commun
November 2024
State Key Laboratory of Organometallic Chemistry and Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), Shanghai, PR China.
The transition metal-catalysed dicarbofunctionalisation of unactivated alkenes normally requires exogenous strong coordinated directing groups, thus reducing the overall reaction efficiency. Here, we report a ligand-enabled Ni(II)-catalysed dicarbofunctionalisation of unactivated alkenes with aryl/alkenyl boronic acids and alkyl halides as the coupling partners with a diverse range of native functional groups as the directing group. This dicarbofunctionalisation protocol provides an efficient and direct route towards vicinal 1,2-disubstituted alkanes using primary, secondary, tertiary amides, sulfonamides, as well as secondary and tertiary amines under redox-neutral conditions that are challenging to access through conventional methods.
View Article and Find Full Text PDFChemistry
November 2024
Department of Chemistry, Indian Institute of Technology Guwahati, Assam, 781039, India.
The first catalytic enantioselective intramolecular allylic dearomatization of allylic alcohol tethered α- and β-naphthols has been developed with iridium/acid-dual catalysis. A wide range of polycyclic spiroketones containing vicinal tertiary and quaternary carbon stereocenters were readily prepared in good to high yields with high diastereo- and moderate to excellent enantioselectivities. An unusual anti-Markovnikov Wacker oxidation has also been shown in synthetic transformations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Schulich Faculty of Chemistry and the, Resnick Sustainability Center for Catalysis, Technion-, Israel Institute of Technology, Haifa, 3200009, Israel.
We report a highly diastereoselective protocol for the synthesis of 1,4- and 1,5-dicarbonyl compounds from densely substituted cyclopropanols. The methodology involves a palladium-catalyzed ring opening reaction followed by a "metal-walk" and oxidation of a remote hydroxyl group. The methodology represents a new application of cyclopropanols as initiation sites for chain walking remote functionalization.
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