Branched selectivity in asymmetric allylic C-H alkylation is enabled by using 2-acylimidazoles as nucleophiles in the presence of a chiral phosphoramidite-palladium catalyst. A wide range of terminal alkenes, including 1,4-dienes and allylarenes, are nicely tolerated and provide chiral 2-acylimidazoles in moderate to high yields and with high levels of regio-, and enantio-, and E/Z-selectivities. Mechanistic studies using density-functional theory calculations suggest a nucleophile-coordination-enabled inner-sphere attack mode for the enantioselective carbon-carbon bond-forming event.
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http://dx.doi.org/10.1002/anie.201908960 | DOI Listing |
J Am Chem Soc
January 2025
New Cornerstone Science Laboratory, State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
The asymmetric Tsuji-Trost reaction has been extensively studied due to its importance in establishing stereogenic centers, often adjacent to an -olefin moiety in organic molecules. The generally preferential formation of chiral -olefin products is believed to result from the thermodynamically more stable -π-allylpalladium intermediate. The rapid associative π-σ-π isomerization makes it challenging to synthesize chiral -olefin products via the transient -π-allylpalladium intermediate.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
Highly stereo- and enantioselective synthesis of δ-alkyl-substituted ()-homoallylic alcohols via asymmetric allylation is developed. In the presence of a chiral phosphoric acid catalyst, allylation of aldehydes with α-substituted allylboronates provides δ-alkyl-substituted homoallylic alcohols with excellent ()-selectivities and enantioselectivities.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
The utilization of β-fluoroamines as pharmaceutical components for drug development has attracted a considerable amount of interest. However, direct access to tertiary β-fluoroamines is challenging. We herein report the rhodium-catalyzed asymmetric amination of tertiary allylic trichloroacetimidates with anilines and cyclic aliphatic amines to access tertiary β-fluoroamines, where the α-carbon atom is bonded to four different substituents, in good yield with high levels of enantioselectivity.
View Article and Find Full Text PDFNat Commun
December 2024
Key Laboratory of Phytochemistry and Natural Medicines, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
The functionalized polycycle with densely contiguous tertiary stereocenters is a formidable challenge in synthesizing the parvistemoline family of Stemona alkaloids. We herein report their catalytic, asymmetric total syntheses in 13-14 steps from commercially available 2-(methoxycarbonyl)-pyrrole, featuring the development and deployment of an Ir/Pd-synergistically-catalyzed allylation of α-non-substituted keto esters with secondary aryl-substituted alcohols, stereodivergently accessible to four stereoisomers. Using chiral Pd-enolate and Ir π-allyl complex under neutral conditions, no epimerization occurs.
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