- Direct Addition of Grignard Reagents to Aliphatic Carboxylic Acids Enabled by Bulky turbo-Organomagnesium Anilides
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The synthesis of ketones through addition of organometallic reagents to aliphatic carboxylic acids is a straightforward strategy that is limited to organolithium reagents. More desirable Grignard reagents can be activated and controlled with a bulky aniline-derived turbo-Hauser base. This operationally simple procedure allows the straightforward preparation of a variety of aliphatic and perfluoroalkyl ketones alike from functionalized alkyl, aryl and heteroaryl Grignard reagents.
- Colas, Kilian,Kohlhepp, Stefanie V.,Mendoza, Abraham,V. D. dos Santos, A. Catarina
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supporting information
(2022/02/02)
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- Mild and direct conversion of esters to morpholine amides using diisobutyl(morpholino)aluminum: Application to efficient one-pot synthesis of ketones and aldehydes from esters
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Morpholine amide intermediates, which are easily prepared by aminolysis of various esters with diisobutyl(morpholino)aluminum, react with organolithium and reducing agents (DIBALH or LDBMA) without isolation of the aminolysis intermediates to give ketones in 83-95% yields and aldehydes quantitatively.
- Jeon, Ah Ram,Kim, Min Eai,Park, Jae Kyo,Shin, Won Kyu,An, Duk Keun
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p. 4420 - 4424
(2014/06/10)
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- Cyanocuprates convert carboxylic acids directly into ketones
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Carboxylic acids were converted directly in 56-99% yields into methyl, n-butyl, and isopropyl ketones using excess cyanocuprates R2CuLi 3 LiCN. A substrate with a stereocenter α to the carboxylic acid was converted into ketones with very little loss of enantiomeric purity. A variety of functional groups were tolerated including aryl bromides. This direct transformation of a carboxylic acid into ketone with minimal tertiary alcohol formation is proposed to involve a relatively stable copper ketal tetrahedral intermediate.
- Genna, Douglas T.,Posner, Gary H.
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supporting information; experimental part
p. 5358 - 5361
(2011/12/15)
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- Empirical method for predicting enantioselectivity in catalytic reactions: demonstration with lipase and oxazaborolidine
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We derived a novel equation capable of predicting the degree of enantioselectivity in a catalytic reaction without any knowledge of the reaction mechanism and/or the transition-state structure, and tested the validity of this equation by changing substrates systematically in the lipase or oxazaborolidine-catalyzed reactions. A good correlation was observed between the predicted and observed E values, and the stereochemistry of the products could be predicted correctly in most cases (28 out of 30).
- Ema, Tadashi,Ura, Norichika,Yoshii, Masataka,Korenaga, Toshinobu,Sakai, Takashi
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experimental part
p. 9583 - 9591
(2010/01/06)
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- The Mn(Salen)-catalyzed oxidative kinetic resolution of secondary alcohols: reaction development and scope
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A series of chiral Mn(Salen) complexes have been synthesized and submitted to the kinetic resolution of secondary alcohols bearing a large hindrance in the biphasic system, which is composed of water and CH2Cl2. After evaluating the appropriate complex, additive, and other conditions, chiral secondary alcohols were obtained with enantiomeric excesses of up to 98.6% in 6 min.
- Cheng, Qigan,Deng, Fanguo,Xia, Chungu,Sun, Wei
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experimental part
p. 2359 - 2362
(2009/04/11)
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- Direct and efficient one-pot preparation of ketones from aldehydes using N-tert-butylphenylsulfinimidoyl chloride
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(Chemical Equation Presented) A general, one-pot process has been established to prepare ketones from aldehydes using N-tert- butylphenylsulfinimidoyl chloride. By employing the developed protocol, a range of unsymmetrical ketones has been prepared in good yields from aldehydes in one simple synthetic operation.
- Crawford, James J.,Henderson, Kenneth W.,Kerr, William J.
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p. 5073 - 5076
(2007/10/03)
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- A convenient preparation of unsymmetrical ketones from borinates using phase transfer catalysis
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Unsymmetrical ketones were prepared from borinates via the insertion of dichlorocarbene into the C-B bond under solid-liquid phase transfer catalysis conditions and oxidation with alkaline hydrogen peroxide in 50-78% yields.
- Guo, Feng,Huang, Shiwen,Shan, Zixing,Zhao, Dejie
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p. 280 - 281
(2007/10/03)
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- One-pot synthesis of ketones using N-methoxy-N-methyl-2-pyridyl urethane
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The one-pot reaction of N-methoxy-N-methyl-2-pyridyl urethane with Grignard and organolithium reagents provided an efficient method for the preparation of unsymmetrical ketones.
- Lee, Na Ra,Lee, Jae In
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p. 1249 - 1255
(2007/10/03)
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- Salt effects on the reactivity and the stability of organomanganese reagents
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The reactivity and the stability of organomanganese reagents prepared from the ate complexes MnX2·2LiBr (X= Br,I) and MnCl2·R4NX (X= Br, Cl) were studied. The preparation and the use for synthetic applications of stable sec- and tert-alkylmanganese bromides in ether as well as the acylation of RMnCl by R'COOCOOEt in THF were successfully achieved for the first time.
- Cahiez, Gerard,Razafintsalama, Lynah,Laboue, Blandine,Chau, Francois
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p. 849 - 852
(2007/10/03)
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- Reactions of in situ formed acyl tributylphosphonium ions with Grignard reagents as an effective route to ketones from acid chlorides
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The reactions of acyl tributylphosphonium ions in situ generated from acid chlorides and Bu3P in THF at -22°C with primary alkyl and arylmagnesium halides have proved to be a convenient and simple procedure to prepare ketones from acid chloride in one-pot.
- Maeda, Hatsuo,Okamoto, Junko,Ohmori, Hidenobu
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p. 5381 - 5384
(2007/10/03)
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- Lewis Acid-Promoted Selective Rearrangement of Trisubstituted Epoxides to Aldehydes or Ketones
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Rearrangement of trisubstituted epoxides has been effected under the influence of various Lewis acids.Among these, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) can be selectively rearranged from trisubstituted epoxides to aldehydes, while
- Maruoka, Keiji,Murase, Noriaki,Bureau, Ronan,Ooi, Takashi,Yamamoto, Hisashi
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p. 3663 - 3672
(2007/10/02)
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- Hindered organoboron groups in organic chemistry. 24. The condensation of aliphatic aldehydes with dimesitylboron stabilised carbanions to give ketones
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The condensation of boron stabilised carbanions, MeS2BCHLiR1, (R1≠H) with aliphatic aldehydes, R2CHO, followed by treatment with trifluoroacetic anhydride (TFAA) or N-chlorosuccinimide (NCS) is an unique, broadly applicable redox process that yields ketones, R1CH2COR2, directly and in high yields. The anion MeS2BCH2Li (MeS2BCHLiR1, R1=H) gives high yields of alkenes, R2CH=CH2 in the same conditions.
- Pelter, Andrew,Smith, Keith,Elgendy, Said M. A.,Rowlands, Martin
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p. 7104 - 7118
(2007/10/02)
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- HINDERED ORGANOBORON GROUPS IN ORGANIC SYNTHESIS. 13. THE DIRECT PRODUCTION OF KETONES FROM ALIPHATIC ALDEHYDES BY A UNIQUE VARIANT OF THE BORON-WITTIG REACTION
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In the presence of trifluoroacetic anhydride or N-chlorosuccinimide, aliphatic aldehydes react with dimesitylboron stabilised carbanions to give after work up, the corresponding ketones, a process wich is unique among Wittig type reactions.Yields of ketones are satisfactory in all cases except those involving the anion derived from the parent compound dimesitylmethylborane, wich give the corresponding alkenes.
- Pelter, Andrew,Smith, Keith,Elgendy, Said,Rowlands, Martin
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p. 5643 - 5646
(2007/10/02)
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- Synthesis and Reactivity toward Acyl Chlorides and Enones of the New Highly Functionalized Copper Reagents RCu(CN)ZnI
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The new and highly functionalized copper reagents RCu(CN)ZnI obtained from readily available primary and secondary alkylzinc iodides by a transmetalation in THF with the soluble salt, CuCN*2LiX, react in good yields with acyl chlorides and enones, respectively, to afford ketones and 1,4-addition products.
- Knochel, Paul,Yeh, Ming Chang P.,Berk, Scott C.,Talbert Jason
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p. 2390 - 2392
(2007/10/02)
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- α-Amino Carbanions. Preparation, Metalation, and Alkylation of Enamidines. Synthesis of Piperidine and Pyrrolidine Natural Products and Homologation of Carbonyl Compounds
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Saturated heterocycles, as their tert-butylformamidines, may be transformed into enamidines, by metalation-selenation-elimination.These enamidines are valuable precursors to 2-substituted, 2,4-disubstituted, and 2,4,6-trisubstituted pyrrolidines, piperidines, and perhydroazepines, prepared in a regiospecific manner.The method is demonstrated by the synthsesis of selenopsin A and the red fire ant venom.The use of acyclic enamidines is displayed as a homologation reagent which converts carbonyl compounds to higher alkyl derivatives.
- Meyers, A. I.,Edwards, Philip D.,Bailey, Thomas R.,Jagdmann, G. Erik
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p. 1019 - 1026
(2007/10/02)
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- N-METHOXY-N-METHYLAMIDES AS EFFECTIVE ACYLATING AGENTS
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Readily preparable N-methoxy-N-methylamides couple in good yields with Grignard and organolithium reagents to produce ketones, and are reduced with hydrides to afford aldehydes.
- Nahm, Steven,Weinreb, Steven M.
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p. 3815 - 3818
(2007/10/02)
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