Formic acid is efficiently used as a C1 source to directly carboxylate allylic alcohols in the presence of a low loading of palladium catalyst and acetic anhydride as additive to afford β,γ-unsaturated carboxylic acids with excellent chemo-, regio-, and stereoselectivity. The reaction proceeds through a carbonylation process with in situ-generated carbon monoxide under mild conditions, avoiding the use of high-pressure gaseous CO. A bisphosphine ligand with a large bite angle (4,5-bis{diphenylphosphino}-9,9-dimethylxanthene, Xantphos) was found to be uniquely effective for this transformation. The regio- and stereoconvergence of this reaction is ascribed to the thermodynamically favored isomerization of the allylic electrophile in the presence of the palladium catalyst.
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http://dx.doi.org/10.1002/chem.201701971 | DOI Listing |
Org 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 PDFFront Chem
December 2024
Department of Chemistry, University of Lucknow, Lucknow, India.
Rhodium(III) catalysis has been used for C-H activation of -nitrosoanilines with substituted allyl alcohols. This method provides an efficient synthesis of the functional -nitroso β-aryl aldehydes and ketones with low catalyst loading, high functional group tolerance, and superior reactivity of allyl alcohols toward -nitrosoanilines. We demonstrated that reaction also proceeds through the one-pot synthesis of -nitrosoaniline, followed by subsequent, C-H activation.
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.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science and Engineering, Xihua University, Chengdu, Sichuan 610039, China.
Fast-charging lithium-ion batteries (LIBs) are the key to solving the range anxiety of electric vehicles. However, the lack of separators with high Li transportation rates has become a major bottleneck, restricting their development. In this work, the electrochemical performance of traditional polyethylene separators was enhanced by coating AlO nanoparticles with a novel green binder.
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