A Formal Metal-Free γ-Arylation of 1,3-Dicarbonyl Compounds via a Sequence of Isomerization/1,4-Addition/[3,3]-Sigmatropic Rearrangement

2021 ◽  
Author(s):  
Shi-Chao Lu ◽  
Fuqiang Wen ◽  
Xidong Guan
Keyword(s):  
Sigmatropic Rearrangement ◽  
Mechanistic Studies ◽  
Dicarbonyl Compounds ◽  
Metal Free

A metal-free redox arylation of alkynes with sulfoxides has been developed to provide an unconventional access to diverse γ-arylated 1,3-dicarbonyl compounds in an atom-economical manner. Mechanistic studies suggest that a...

scholarly journals Metal‐Free Deoxygenation of Amine N–Oxides: Synthetic and Mechanistic Studies

ChemPhysChem ◽  
2021 ◽  
Author(s):  
Sami Lakhdar ◽  
William Lecroq ◽  
Jules Schleinitz ◽  
Mallaury Billoue ◽  
Anna Perfetto ◽  
...  
Keyword(s):  
Mechanistic Studies ◽  
Metal Free

Bifunctional metal-free photo-organocatalysts for enantioselective aerobic oxidation of β-dicarbonyl compounds

Tetrahedron ◽  
2018 ◽  
Vol 74 (27) ◽  
pp. 3624-3633 ◽  
Author(s):  
Xiao-fei Tang ◽  
Shi-hao Feng ◽  
Ya-kun Wang ◽  
Fan Yang ◽  
Ze-hao Zheng ◽  
...  
Keyword(s):  
Aerobic Oxidation ◽  
Dicarbonyl Compounds ◽  
Metal Free

scholarly journals Intermolecular 3+3 Ring Expansion of Aziridines to Dehydropiperidines through the Intermediacy of Aziridinium Ylides

2019 ◽  
Author(s):  
Jennifer Schomaker ◽  
Josephine Eshon ◽  
Kate A. Nicastri ◽  
Steven C. Schmid ◽  
William T. Raskopf ◽  
...  
Keyword(s):  
Natural Product ◽  
Functional Group ◽  
Ring Expansion ◽  
Sigmatropic Rearrangement ◽  
Reactive Intermediate ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Complex Molecules ◽  
Form Complex ◽  
Reaction Proceeds

Bicyclic aziridines undergo formal [3+3] ring expansion reactions when exposed to rhodium-bound vinyl carbenes to form complex dehydropiperidines in a highly stereocontrolled rearrangement. Mechanistic studies and DFT computations indicate the reaction proceeds through the formation of a vinyl aziridinium ylide; this reactive intermediate undergoes a concerted, asynchronous, pseudo-[1,4]- sigmatropic rearrangement to directly furnish the heterocyclic products with net retention at the new C-C bond. In combination with an asymmetric silver-catalyzed aziridination developed in our group, this method quickly delivers enantioenriched scaffolds with up to three contiguous stereocenters. The mild reaction conditions, functional group tolerance, and high stereochemical retention of this method are especially well-suited for appending piperidine motifs to natural product and complex molecules. Ultimately, our work establishes the value of underutilized aziridinium ylides as key intermediates in strategies to convert small, strained rings to larger N-heterocycles.

I2/TBHP-Promoted Approach to α-Keto Esters from Trifluoromethyl β-Diketones and Alcohols via C–C Bond Cleavage

Synlett ◽  
2017 ◽  
Vol 28 (15) ◽  
pp. 2018-2023 ◽  
Author(s):  
Xiang Fang ◽  
Xueyan Yang ◽  
Tongle Shao ◽  
Jun Zhou ◽  
Chen Jin ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Coupling Reaction ◽  
Mechanistic Studies ◽  
Metal Free ◽  
Oxidation Pathway ◽  
Keto Esters ◽  
Oxidative Coupling Reaction

A metal-free oxidative coupling reaction of trifluoromethyl β-diketones with alcohols for the synthesis of α-keto esters in good to excellent yields has been developed. Preliminary mechanistic studies suggest that an I2/TBHP promoted sequential iodination, C–C bond cleavage, C–O bond formation and oxidation pathway is involved in this reaction.

Photoinduced Oxidative Cross-Coupling for O–S Bond Formation: A Facile Synthesis of Alkyl Benzenesulfonates

Synlett ◽  
2017 ◽  
Vol 28 (13) ◽  
pp. 1558-1563 ◽  
Author(s):  
Aiwen Lei ◽  
Atul Singh ◽  
Hong Yi ◽  
Guoting Zhang ◽  
Changliang Bian ◽  
...  
Keyword(s):  
Visible Light ◽  
Bond Formation ◽  
Cross Coupling ◽  
Selective Synthesis ◽  
Mechanistic Studies ◽  
Facile Synthesis ◽  
Metal Free

We have developed a photoinduced oxidative cross-coupling of thiophenols with alcohols for O–S bond formation. The protocol uses visible light, a metal-free photocatalyst, and oxygen as the oxidant for the selective synthesis of alkyl benzenesulfonates; no ligand co-additive is necessary. Mechanistic studies suggested that the disulfide and alkyl benzenesulfinate are involved as intermediates and that the transformation proceeds by a radical pathway.

scholarly journals Boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with silylborane and an alkoxy base: expanded scope and mechanistic studies

2015 ◽  
Vol 6 (5) ◽  
pp. 2943-2951 ◽  
Author(s):  
Eiji Yamamoto ◽  
Satoshi Ukigai ◽  
Hajime Ito
Keyword(s):  
Transition Metal ◽  
Mechanistic Studies ◽  
Metal Free

A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides using a silylborane/alkoxy-base reagent. Borylation of (Z)-alkenyl halides proceeded in a stereoretentive manner.

Deuterated Aryl Alkyl Ethers Synthesis via Nucleophilic Etherification of Aryl Alkyl Ethers and Thioethers with Deuterated Alcohols

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1805-1809
Author(s):  
Shuai Li ◽  
Xia Wang ◽  
Xin-Ge Yang ◽  
Gui-Quan Yu ◽  
Xue-Qiang Wang
Keyword(s):  
Transition Metal ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Alkyl Ethers

A transition-metal-free etherification protocol that is capable of synthesizing deuterated ethers is described. A wide range of aryl alkyl ethers and thioethers were suitable for this transformation owing to the mild reaction conditions. Besides, a series of sterically bulky deuterated alcohols were successfully incorporated into cyano-substituted arenes. The results of mechanistic studies suggested this reaction might take place via nucleophilic aromatic substitution pathway.

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