- Effective palladium-catalyzed hydroxycarbonylation of aryl halides with substoichiometric carbon monoxide
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A protocol for the Pd-catalyzed hydroxycarbonylation of aryl iodides, bromides, and chlorides has been developed using only 1-5 mol % of CO, corresponding to a pCO as low as 0.1 bar. Potassium formate is the only stoichiometric reagent, acting as a mildly basic nucleophile and a reservoir of CO. The substoichiometric CO could be delivered to the reaction from an acyl-Pd(II) precatalyst, which provides both the CO and an active catalyst, and thereby obviates the need for handling a toxic gas.
- Korsager, Signe,Taaning, Rolf H.,Skrydstrup, Troels
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supporting information
p. 2891 - 2894
(2013/04/10)
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- The first regioselective metalation and functionalization of unprotected 4-halobenzoic acids
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(Chemical Equation Presented) By treatment with s-BuLi, s-BuLi/TMEDA, or t-BuLi at ～-78°C, 4-fluoro- and 4-chlorobenzoic acids (1a,b) are metalated preferentially in the position adjacent to the carboxylate. A complete reversal in regioselectivity is observed for 1a when treated with LTMP; a sequential process involving a rapid intraaggregate lithiation through a quasi dianion complex "QUADAC" is postulated to explain the unusual reactivity of Me2S2 and I2.
- Gohier, Frederic,Castanet, Anne-Sophie,Mortier, Jacques
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p. 1501 - 1504
(2007/10/03)
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- Two-step production of 3-chloro-4-fluoro-benzoyl chloride by chlorination
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The present invention relates to a process for the preparation of 3-chloro-4-fluorobenzoyl chloride which comprises reacting 4-fluorobenzaldehyde with a chlorinating agent in the presence of a free-radical initiator in the presence or absence of a solvent at from ?20 to 200° C. to give 4-fluorobenzoyl chloride, and reacting the 4-fluorobenzoyl chloride with a chlorinating agent in the presence of a chlorination catalyst in the presence or absence of a solvent at from ?20 to 200° C. to give 3-chloro-4-fluorobenzoyl chloride.
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