- Silylamination of electrophilic alkynes
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The addition of simple silylamines to dialkyl acetylenecarboxylates was investigated yielding both E and Z-silylenamines in contrast to an earlier report. Silylamination was also achieved with propiolates, expanding the scope of the silylamination reactio
- Baines, Kim M.,McOnie, Sarah L.
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supporting information
(2021/12/23)
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- An expedient synthesis of highly functionalized 1,3-dienes by employing cyclopropenes asC4units
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An efficient method has been described to synthesize dicarbonyl functionalized 1,3-dienes by cleaving the CC bond of enaminones with cyclopropenes in the presence of a rhodium catalyst. The acetate-substituted cyclopropenes are judiciously chosen as standardC4units of 1,3-diene precursors. The reactions are believed to undergo a unique cutting and insertion process, involving a CC bond cleavage of the enaminone and insertion of a newC(sp2) source with the formation of two C-C single bonds. A broad range of substrates can be used to synthesize the corresponding 1,3-dienes under very mild reaction conditions, including low catalyst-loading, ambient temperature, and a neutral reaction solvent.
- Jiang, Chengzhou,Wu, Jiamin,Han, Jiabin,Chen, Kai,Qian, Yang,Zhang, Zhengyu,Jiang, Yaojia
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supporting information
p. 5710 - 5713
(2021/06/16)
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- Formation of Enamines via Catalytic Dehydrogenation by Pincer-Iridium Complexes
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Di-isopropylphosphino-substituted pincer-ligated iridium catalysts are found to be significantly more effective for the dehydrogenation of simple tertiary amines to give enamines than the previously reported di-t-butylphosphino-substituted species. It is
- Lu, Yansong J.,Zhang, Xiawei,Malakar, Santanu,Krogh-Jespersen, Karsten,Hasanayn, Faraj,Goldman, Alan S.
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supporting information
p. 3020 - 3028
(2020/03/23)
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- Synthesis of Functionalized α-Vinyl Aldehydes from Enaminones
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An efficient RhII-catalyzed synthesis of functionalized α-vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C?C bond cleavage of the cyclopropane intermediates leads to formation of α-vinyl aldehyde derivatives with high E/Z selectivity. This method proceeds at room temperature under very mild reaction conditions and works with a broad substrate scope.
- Chen, Jie,Guo, Pan,Zhang, Jianguo,Rong, Jiaxin,Sun, Wangbin,Jiang, Yaojia,Loh, Teck-Peng
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supporting information
p. 12674 - 12679
(2019/08/07)
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- Synthesis of 2-aminofurans and 2-unsubstituted furans via carbenoid-mediated [3 + 2] cycloaddition
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An efficient dual synthetic manifold for 2-aminofurans and 2-unsubstituted furans has been developed. The carbenoid-mediated [3 + 2] cycloaddition of copper carbenoids with enamines provides 2-amino-2,3-dihydrofurans which serve as common intermediates for both 2-aminofurans and 2-unsubstituted furans. The Royal Society of Chemistry 2012.
- Jiang, Yaojia,Khong, Vanessa Zhong Yue,Lourdusamy, Emmanuvel,Park, Cheol-Min
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experimental part
p. 3133 - 3135
(2012/05/04)
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- ENZYMATIC SYNTHESIS OF CARBA-NAD
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The disclosure concerns the enzymatic synthesis of stable analogues of nicotinamide adenine dinucleotide NAD/NADH and nicotinamide adenine dinucleotide phosphate NADP/NADPH, the so-called “carba-NADs”, i.e. analogues of NAD/NADH or NADP/NADPH, respectively, comprising a carbacyclic sugar instead of ribose.
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Page/Page column 3-4
(2012/06/01)
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- METHOD AND SUBSTANCES FOR PREPARATION OF N-SUBSTITUTED PYRIDINIUM COMPOUNDS
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The present invention relates to a method for the synthesis of N-substituted carboxylated pyridinium compounds by reacting a pentamethine precursor with a primary amine. In this reaction an N-substituted alkoxycarbonyl pyridinium heterocycle is formed.
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Page/Page column 8-9
(2011/02/24)
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- A new synthesis of alkyl (E)-(3-dimethylamino)acrylates
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A highly stereoselective one-step method for the synthesis of alkyl (E)-(3-dimethylamino)acrylates from N,N-dimethylformamide and ketene acetals is reported.
- Robertson, Jeffrey M.,Jones, Ian W.,Kayne, Kevin M.,Contreras, Cristina G.,Witter, Daniel J.,Bates, Robert B.,Hall Jr.
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experimental part
p. 6080 - 6081
(2011/11/29)
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- Stereoselective synthesis of α-Diazo oxime ethers and their application in the synthesis of highly substituted pyrroles through a [3+2] cycloaddition
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The stereoselective diazo transfer reaction with oxime ethers offers an efficient route to the corresponding α-diazo oxime ethers. The utility of these compounds has been demonstrated by the synthesis of highly substituted pyrroles through a [3+2] cycloaddition of α-oximino carbenoids with enamines (see scheme).
- Lourdusamy, Emmanuvel,Yao, Lin,Park, Cheol-Min
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supporting information; experimental part
p. 7963 - 7967
(2011/01/08)
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- Efficient synthesis of β-enaminoesters via highly stereoselective Reformatsky reaction with disubstituted formamides as novel electrophiles
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An efficient synthesis of various β-enaminoesters has been achieved via Reformatsky reaction with disubstituted formamides as novel electrophiles. The exclusive β-enaminoester E-isomers were obtained in 60-72% yield.
- Ke, Yi-Yin,Li, Yu-Jin,Jia, Jian-Hong,Sheng, Wei-Jian,Han, Liang,Gao, Jian-Rong
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experimental part
p. 1389 - 1391
(2009/06/08)
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- Studies towards the biomimetic synthesis of pyridomacrolidin
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A possible biomimetic synthesis of pyridomacrolidin has been proposed and experimentally supported by carrying out a model study. Regio and stereospecific [3+2] cycloaddition of an in situ generated unusual di-tert-butylated acyl nitrone with Z-2-cyclodecenone and subsequent aromatisation was the key step in our proposed biomimetic synthesis. Finally a pyridomacrolidin analogue was prepared via Friedel-Crafts di-de-t-butylation of the cycloadduct.
- Irlapati, Nageswara Rao,Baldwin, Jack E.,Adlington, Robert M.,Pritchard, Gareth J.,Cowley, Andrew R.
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p. 4603 - 4614
(2007/10/03)
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- An unusual oxidative cyclization: Studies towards the biomimetic synthesis of pyridomacrolidin
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(Matrix presented) An unusual oxidative cyclization of a N-hydroxy pyridone 9 with Z-2-cyclodecenone 11 has been achieved, thus demonstrating a possible biomimetic route to pyridomacrolidin 2.
- Irlapati, Nageswara Rao,Baldwin, Jack E.,Adlington, Robert M.,Pritchard, Gareth J.,Cowley, Andrew
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p. 2351 - 2354
(2007/10/03)
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- Novel [6 + 2] cycloaddition of fulvenes with alkenes: a facile synthesis of the anislactone and hirsutane framework.
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[reaction: see text] In contrast to the Diels-Alder reaction of fulvenes and various alkenes, 6-aminofulvenes react with maleic anhydride (or maleimide) to give [6 + 2] cycloaddition adducts, constituting an efficient and novel route to pentaleno[1,2-c]furan, pentaleno[1,2-c]pyrrole, and cyclopenta[a]pentalene skeleton.
- Hong, Bor-Cherng,Shr, Yeong-Jou,Wu, Jian-Lin,Gupta, Arun Kumar,Lin, Kuan-Jiuh
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p. 2249 - 2252
(2007/10/03)
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- A study of Aryl radical cyclization in enaminone esters
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Aryl radical cyclization in N-phenyl, N-benzyl, and N-phenethyl enaminone esters 1a-f was studied. N-Benzyl and N-phenethyl enaminones afforded 5-exo and 6-exo cyclization products, respectively, but radical cyclization did not occur in N-phenyl enaminones. The rate constants for the 5-exo and 6-exo cyclization processes in secondary enaminones were estimated as being on the order of 107 s-1 at 353 K; since DNMR experiments showed the rate constant for rotation around the enaminone C3-N bond to be on the order of 104 s-1 at this temperature, the initial enaminone configuration is maintained throughout the cyclization process. PM3 calculations suggested that the nonoccurrence of endo and 4-exo cyclizations is due to the corresponding transition structures involving significant distortion of the conjugated enaminone system.
- Navarro-Vazquez, Armando,Garcia, Alberto,Dominguez, Domingo
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p. 3213 - 3220
(2007/10/03)
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- Single Electron Transfer Induced Total Synthesis of Canthin-6-one
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The cytotoxic alkaloid canthin-6-one was synthesized from harmalane in a short sequence (six steps) with good overall yield (18 percent) using a single electron transfer (SET) induced radical cationic hetero [4+2] cycloaddition as high yielding key step.
- Roessler, Ulrich,Blechert, Siegfried,Steckhan, Eberhard
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p. 7075 - 7078
(2007/10/03)
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- Process for the preparation of β- aminoacrylic acid esters
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β-Aminoacrylic acid esters can be prepared by reacting acetic acid esters of the formula with aminal esters of the formula STR1 at 0.5-10 bar and 50°-170° C. in an aprotic polar solvent. The radicals R1 to R7 are as defined in the description.
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- STUDIES ON DIMETHYLHYDRAZONES OF HETEROARYL ALDEHYDES. THE REACTIVITY OF 2-FORMYLFURAN, 2-FORMYLTHIOPHENE AND 1-METHYL-2-FORMYLPYRROLE N,N-DIMETHYLHYDRAZONES WITH METHYL PROPIOLATE AND DIETHYL AZODICARBOXYLATE
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The title hydrazones react with methyl propiolate giving the new 2-heteroarylpyridines (4, 5 and 6).The reaction with diethyl azodicarboxylate gives 1:1 Michael adducts except with formylthiophene hydrazone that gives the compound (14) a novel type of 1:1 adduct.
- Abarca, Belen,Ballesteros, Rafael,Gonzalez, Eugenia,Sancho, Pedro,Sepulveda, Jose,Soriano, Concepcion
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p. 1811 - 1817
(2007/10/02)
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- ADDITIONS DES FONCTIONS >NH ET >P(O)H SUR LA DOUBLE LIAISON DES VINYL SPIROPHOSPHORANES SYNTHESE DES α ET β AMINO SPIROPHOSPHORANES ALCOOLYSE DE LA LIAISON P-C DANS LES COMPOSES D'ADDITION OBTENUS
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Addition of amines and of hydrogenphosphonates on the carbon-carbon double bond belonging to vinylphosphoranes is examined.The stereochemistry and reactivity of the saturated adducts obtained is rationalized.Alcoholysis of the P-C bond is also studied.
- Burgada, Ramon,Mohri, Ali
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- Group Transfer Reactions. - Tetracarbonylferrates from Orthoformic Acid Derivatives and Pentacarbonyliron
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The nucleophilic leaving group X is transferred from orthoformic acid derivatives HC(NR2)X (X= NR2, OR, CN) to Fe(CO)5.No such reactions were observed between 4 and amide acetals (HCX2NR2) or ortho ester derivatives HCX3 (X= OR, SR).The structures of the transition metal-acyl complexes obtained have been determined by IR and NMR spectra.In the case of the reaction of tris(dimethylamino)methane (3a) with 4 the equilibrium between the resulting amidinium-carbamoyltetracarbonylferrate complex 5a and the starting materials was investigated.The equilibrium is shifted completely in favor of the ionic compound 5a.However, 3a could be isolated by extraction of this solution with an apolar solvent.Alkylation of 5a with triethyloxonium tetrafluoroborate leads to the tetracarbonyliron-carbene complex 13.Reaction of 5a with acrylonitrile or methyl acrylate by addition of both the nucleophile "NR2-" and the electrophile + and subsequent eliminations gives the β-dimethylamino substitution product 18 and 21, respectively.In contrast 3a induces polymerisation of acrylonitrile.
- Daub, Joerg,Hasenhuendl, Adelheid,Krenkler, Karl P.,Schmetzer, Johannes
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p. 997 - 1015
(2007/10/02)
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