- Direct Amidation of Esters by Ball Milling**
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The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This direct synthesis platform has been applied to the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals as well as the gram-scale synthesis of an active pharmaceutical, all in the absence of a reaction solvent.
- Barreteau, Fabien,Battilocchio, Claudio,Browne, Duncan L.,Godineau, Edouard,Leitch, Jamie A.,Nicholson, William I.,Payne, Riley,Priestley, Ian
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supporting information
p. 21868 - 21874
(2021/09/02)
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- Biosyntheses of geranic acid and citronellic acid from monoterpene alcohols by Saccharomyces cerevisiae
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Geraniol is one of the important aromatic ingredients in alcoholic beverages. Bioconversions of geraniol to other terpenoids and genes involved in the oxidation of geraniol were investigated. Geranic acid and citronellic acid were detected in yeast culture, where geraniol or nerol was added. Addition of citral, a mixture of geranial and neral, resulted in the production of geranic acid and citronellic acid, whereas the addition of citral or citronellal resulted in the production of citronellic acid, suggesting that citronellic acid might be produced through the conversion of citral to citronellal followed by the oxidation of citronellal. Consumption of geraniol and production of geranic acid, citronellic acid, and citronellol were affected in adh1Δ, adh3Δ, adh4Δ, and sfa1Δyeast strains, which possess single deletion of a gene encoding alcohol dehydrogenase. This is the first report of the bioconversion of monoterpene alcohols, geraniol and nerol, to geranic acid and citronellic acid in yeast culture.
- Huang, Shuai,Maeda, Isamu,Ohashi, Yuka
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p. 1530 - 1535
(2021/08/13)
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- Aerobic Photooxidative Synthesis of β-Alkoxy Monohydroperoxides Using an Organo Photoredox Catalyst Controlled by a Base
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Transition-metal-free synthesis of β-alkoxy monohydroperoxides via aerobic photooxidation using an acridinium photocatalyst was developed. This method enables the synthesis of some novel hydroperoxides. The peroxide source is molecular oxygen, which is cost-effective and atomically efficient. Magnesium oxide plays an important role as a base in the catalytic system.
- Asano, Yuya,Nagasawa, Yoshitomo,Yamaguchi, Eiji,Itoh, Akichika
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supporting information
p. 409 - 412
(2018/02/21)
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- γ-Lactone Synthesis via Palladium(II)-Catalyzed Lactonization of Unactivated Methylene C(sp3)-H Bonds
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A palladium(II)-catalyzed intramolecular lactonization of unactivated methylene C(sp3)-H bonds using PIP bidentate auxiliary is described. This method provides an efficient and concise pathway to synthesize functionalized γ-lactones.
- Liu, Bin,Shi, Bing-Feng
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supporting information
p. 2396 - 2400
(2016/09/28)
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- Nickel-catalyzed dehydrogenative cross-coupling: Direct transformation of aldehydes into esters and amides
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By exploring a new mode of nickel-catalyzed cross-coupling, a method to directly transform both aromatic and aliphatic aldehydes into either esters or amides has been developed. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. Mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C-H bond is also presented.
- Whittaker, Aaron M.,Dong, Vy M.
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supporting information
p. 1312 - 1315
(2015/01/30)
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- N-Heterocyclic carbene-catalyzed oxidations
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N-Heterocyclic carbenes catalyze the oxidation of allylic and benzylic alcohols as well as saturated aldehydes to esters with manganese(IV) oxide in excellent yields. A variety of esters can be synthesized, including protected carboxylates. The oxidation proceeds under mild conditions, with low loadings of a simple triazolium salt pre-catalyst in the presence of base. Substrates containing potentially epimerizable centers are oxidized while preserving stereochemical integrity. The acyl triazolium intermediate generated under catalytic conditions can be employed as a chiral acylating agent in the desymmetrization of meso-diols.
- Maki, Brooks E.,Chan, Audrey,Phillips, Eric M.,Scheidt, Karl A.
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experimental part
p. 3102 - 3109
(2009/09/05)
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- N-heterocyclic carbene-catalyzed oxidation of unactivated aldehydes to esters
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(Chemical Equation Presented) N-Heterocyclic carbenes catalyze the oxidation of unactivated aldehydes to esters with manganese(IV) oxide in excellent yield. The reaction proceeds through a transient activated alcohol, which when generated in situ allows for the selective oxidation of the aldehyde under mild conditions. These conditions successfully oxidize potentially epimerizable aldehydes and alcohols while preserving stereochemical integrity. A variety of ester derivatives can be synthesized with variation of the acylated alcohol as well as the unactivated aldehyde.
- Maki, Brooks E.,Scheldt, Karl A.
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supporting information; experimental part
p. 4331 - 4334
(2009/06/06)
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- Regio- and Stereoselective Hydrogenation of Conjugated Carbonyl Compounds via Palladium Assisted Hydrogen Transfer by Ammonium Formate
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Excellent regio- and stereoselectivity has been achieved in the hydrogenation of C=C bond conjugated to carbonyl group in presence of olefin by ammonium formate/Pd-C system.
- Ranu, Brindaban C.,Sarkar, Arunkanti
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p. 8649 - 8650
(2007/10/02)
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- OZONOLYSIS OF ALKENES AND THE REACTIONS OF POLYFUNCTIONAL COMPOUNDS LIII.SYNTHESIS OF THE ESTERS OF 2,3-DIHYDRO DERIVATIVES OF TRI-, DI-, AND MONOPRENOIC ACIDS
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The esters of the 2,3-dihydro derivatives of geranylgeranic, farnesylic, and geranic acids (di-, sesqui-, and monoterpenoid acids) were synthesized from the products from ozonolysis of 1,5,9-trimethyl-1E,5E,9E-cyclododecatriene.
- Odinokov, V. N.,Kukovinets, O. S.,Sakharova, N. I.,Tolstikov, G. A.
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- SELECTIVE REDUCTION OF α,β-UNSATURATED ESTERS IN THE PRESENCE OF OLEFINS
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Several α,β-unsaturated esters containing also isolated olefins or other functionalities subject to saturation were selectively reduced to the corresponding saturated esters by magnesium in methanol.
- Hudlicky, T.,Sinai-Zingde, G.,Natchus, M. G.
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p. 5287 - 5290
(2007/10/02)
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- GENERATION OF AN ACTIVE ACYL SPECIES FROM STABLE 1-METHYL-2-ACYL-1H-IMIDAZOLES
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1-Methyl-2-(1'-cyano-1'-trimethylsilyloxy)alkyl-1H-imidazoles (2) were easily prepared from the corresponding stable carbonyl compounds, 1-methyl-2-acyl-1H-imidazoles (1).When the quarternary salts of 2 were treated with various nucleophiles, reactive acyl species, which was presumed to be acylcyanide (12), was generated in situ under C-C bond fission to result in producing the corresponding acylated compounds (5-10) in good yields.
- Ohta, Shunsaku,Hayakawa, Satoshi,Okamoto, Masao
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p. 5681 - 5684
(2007/10/02)
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- A NOVEL METHOD FOR THE TERPENE SYNTHESIS BY THE RING-OPENING REACTION OF β-METHYL-β-PROPIOLACTONE
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A new route for the terpene synthesis is investigated, which undergoes via terpene carboxylic acids as key intermediates obtained by the regiospecific ring opening of β-methyl-β-propiolactone with cuprate or with a Grignard reagent in the presence of a copper catalyst.
- Fujisawa, Tamotsu,Sato, Toshio,Kawara, Tatsuo,Noda, Atsunari,Obinata,Toshiyuki
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p. 2553 - 2554
(2007/10/02)
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