- Nickel-Catalyzed Activation of Acyl C-O Bonds of Methyl Esters
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We report the first catalytic method for activating the acyl C-O bonds of methyl esters through an oxidative-addition process. The oxidative-addition adducts, formed using nickel catalysis, undergo in situ trapping to provide anilide products. DFT calculations are used to support the proposed reaction mechanism, to understand why decarbonylation does not occur competitively, and to elucidate the beneficial role of the substrate structure and the Al(OtBu)3 additive on the kinetics and thermodynamics of the reaction.
- Hie, Liana,Fine Nathel, Noah F.,Hong, Xin,Yang, Yun-Fang,Houk, Kendall N.,Garg, Neil K.
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Read Online
- Highly efficient aminocarbonylation of iodoarenes at atmospheric pressure catalyzed by a robust acenaphthoimidazolyidene allylic palladium complex
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A robust allylic palladium-NHC complex was developed and exhibited extremely high catalytic activity toward aminocarbonylation of various (hetero)aryl iodides under atmospheric carbon monoxide pressure, in which a broad range of secondary and primary amines were well tolerated. In addition, the concise synthesis of an anticancer drug tamibarotene was accomplished even in a gram scale, further highlighting the practical applicability of the protocol.
- Fang, Weiwei,Deng, Qinyue,Xu, Mizhi,Tu, Tao
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supporting information
p. 3678 - 3681
(2013/08/23)
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- Radical OfC transposition: A metal-free process for conversion of phenols into benzoates and benzamides
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We report a metal-free procedure for transformation of phenols into esters and amides of benzoic acids via a new radical cascade. Diaryl thiocarbonates and thiocarbamates, available in a single high-yielding step from phenols, selectively add silyl radicals at the sulfur atom of the CdS moiety. This addition step, analogous to the first step of the Barton-McCombie reaction, produces a carbon radical which undergoes 1,2 OfC transposition through an O-neophyl rearrangement. The usually unfavorable equilibrium in the reversible rearrangement step is shifted forward via a highly exothermic C-S bond scission in the O-centered radical, which furnishes the final benzoic ester or benzamide product. The metal-free preparation of benzoic acid derivatives from phenols provides a potentially useful alternative to metal-catalyzed carbonylation of aryl triflates.
- Baroudi, Abdulkader,Alicea, Jeremiah,Flack, Phillip,Kirincich, Jason,Alabugin, Igor V.
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scheme or table
p. 1521 - 1537
(2011/06/11)
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- Metal-free transformation of phenols into substituted benzamides: A highly selective radical 1,2-O→C transposition in O-aryl-N-phenylthiocarbamates
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Radical merry-go-round: A highly efficient metal-free transformation of phenols into benzamides is designed through one-step conversion of phenols to aryl thiocarbamates and a subsequent radical addition/rearrangement/ fragmentation cascade. Computational analysis fully rationalizes the experimentally observed selectivity. Despite the possible competition from N-C fragmentation and N-neophyl rearrangement, the transformation exclusively follows the most kinetically and thermodynamically favored O-neophyl rearrangement path.
- Baroudi, Abdulkader,Flack, Phillip,Alabugin, Igor V.
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supporting information; experimental part
p. 12316 - 12320
(2010/12/29)
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