43108-63-0Relevant academic research and scientific papers
New method for the synthesis of 2-aza-1,3-butadienes
Sisak, Attila
, p. 3693 - 3702 (2007/10/03)
2-Aza-1,3-butadienes have been synthesized from carbonyl compounds and 1,1,1,3,3,3-hexamethyl-disilazane in the presence of cobalt-containing catalysts. The best yields (up to 95%) were achieved in the case of aldehydes branched in the α-position and 2-methylcyclohexanone. In the case of two α,β-unsaturated ketones, pyridine derivatives were found as the main products. Copyright Taylor & Francis Group, LLC.
1,4-Silatropy of S-α-silylbenzyl thioesters: A convenient route to silyl enol and dienol ethers accompanied by C-C bond formation via thiocarbonyl ylides
Choi, Jinil,Imai, Eiichiro,Mihara, Masatoshi,Oderaotoshi, Yoji,Minakata, Satoshi,Komatsu, Mitsuo
, p. 6164 - 6171 (2007/10/03)
A novel convenient method for the generation of thiocarbonyl ylides from readily accessible starting materials and the first synthetic application of in situ generated ylides in the synthesis of silyl enol and dienol ethers, accompanied by C-C bond formation, is described. Under completely neutral conditions without any catalyst or additive, thermal reactions of S-α-silylbenzyl thioesters in sealed tubes at 180 °C provided silyl enol and dienol ethers in good to excellent yields with high stereoselectivities. This procedure consists of a multistep reaction in a one-pot process, i.e., 1,4-silatropy of S-α-silylbenzyl thioesters to give thiocarbonyl ylides, 1,3-electrocyclization of the ylides to give thiiranes, and the extrusion of sulfur from thiiranes to give silyl enol and dienol ethers.
A novel synthesis of silyl enol ethers from α-silylbenzylthiols and carboxylic acid derivatives via C-C bond formation; thermal rearrangement of S-α-silylbenzyl thioesters
Komatsu, Mitsuo,Jinil, Choi,Imai, Eiichiro,Oderaotoshi, Yoji,Minakata, Satoshi
, p. 9221 - 9223 (2007/10/03)
A new procedure for the synthesis of silyl enol ethers from S-α-silylbenzyl thioesters without need for either bases or catalysts via C-C bond formation is described. Solutions of S-α-silylbenzyl thioesters were simply heated at 180°C for 24 h in a sealed tube to give silyl enol ethers in good yields with high stereoselectivity. Cyclization of the dipoles generated by thermal rearrangement of the silyl group and elimination of sulfur afforded silyl enol ethers.
Regioselective synthesis of substituted (3E)-1,3-dienes from chelated allyl-ironcarbene complexes and potassium enoxyborates
B?hmer, Jutta,Hampel, Frank,Schobert, Rainer
, p. 661 - 667 (2007/10/03)
The addition of potassium enoxyborates to the chelated allyl-ironcarbene complex 1 leads to the corresponding η-(3E)-1,3-diene complexes 2 in fair yields. Complexes 2 can be demetalated with ceric ammonium nitrate (CAN) to give unrearranged (3E)-6-oxo-1.3-dienes 3. Prior to decomplexation, the carbonyl group can be further modified. This is demonstrated by the syntheses of the natural terpene alcohol hotrienol and of a complexed methylene- separated dienyne. Potassium enoxyborates are superior to lithium enolates as they are readily prepared in situ from a variety of aldehydes and ketones which do not form sufficiently stable lithium derivatives. In contrast to lithium enolates, only C- C coupling products derived from the 'kinetic' regioisomers are formed from unsymmetrical aliphatic ketones.
REGIOSELECTIVE PREPARATION OF KINETIC TRIMETHYLSILYL ENOL ETHERS FROM β-KETO SILANES
Yamamoto, Yohsuke,Ohdoi, Keisuke,Nakatani, Masayuki,Akiba, Kin-ya
, p. 1967 - 1968 (2007/10/02)
Kinetic trimethylsilyl enol ethers were prepared regioselectively by the two-step method, i.e., trimethylsilyl triflate catalyzed rearrangement of β-keto silanes which were prepared from trimethylsilylmethylcopper and acid chlorides.
HIGHLY SELECTIVE, KINETICALLY CONTROLLED ENOLATE FORMATION USING LITHIUM DIALKYLAMIDES IN THE PRESENCE OF TRIMETHYLCHLOROSILANE
Corey, E. J.,Gross, Andrew W.
, p. 495 - 498 (2007/10/02)
The deprotonation of ketones and esters with lithium dialkylamides in the presence of trimethylchlorosilane leads to enhanced selectivity for the kinetically generated enolate.Lithium t-octyl-t-butylamide is shown to be superior to lithium diisopropylamid
Carbon-Carbon Bond Formation by the Use of Chloroiodomethane as a C1 Unit. III. A Convenient Synthesis of the Mannich Base from Enol Silyl Ether by a Combination of Chloroiodomethane and N,N,N',N'-Tetramethylmethanediamine
Miyano, Sotaro,Hokari, Hiroshi,Hashimoto, Harukichi
, p. 534 - 539 (2007/10/02)
The Mannich dimethylaminomethylation of carbonyl compounds is conveniently carried out via enol trimethylsilyl ethers by a combination of chloroiodomethane (CH2ClI) and N,N,N',N'-tetramethylmethanediamine (TMMD) in DMSO as the solvent at ambient temperatute.The mechanism of the transformation is discussed on the basis of product analysis and 1H NMR spectral studies.The reagent system CH2ClI/TMMD also provides a convenient route to the Eschenmoser's salt ().
ETUDE DANS LA SERIE DES ORGANOSILYLAZOLES. II. REACTION D'ADDITION NUCLEOPHILE SUR LES DERIVES CARBONYLES
Gasparini, J.P.,Gassend, R.,Maire, J.C.,Elguero, J.
, p. 309 - 315 (2007/10/02)
The reactivity of organosilicon amines of imidazole, 1,2,4-triazole and benzotriazole towards aldehydes and ketones has been studied.Aldehydes react easily and give the addition products at room temperature.With ketones, the reactions depend both on the organosilicon amine and the ketone used.With trimethylsilyl-1 imidazole, ketones having an enolic form stabilized by conjugation, form enoxysilanes.
Reactions of Trialkylsilyl Trifluoromethanesulfonates, I. - Synthesis of Trialkylsilyl Enol Ethers
Emde, Herbert,Goetz, Andreas,Hofmann, Karin,Simchen, Gerhard
, p. 1643 - 1657 (2007/10/02)
The reactions of the ketones 2,2-bromoketones 6, α,β-unsaturated ketones 8, 1,2-diketones, and aliphatic aldehydes 20 with trialkylsilyl triflates 1 in the presence of triethylamine (4) at room temperature yield the silyl enol ethers 3, 7, 9, 11, and 21.The silylation of the unsymmetrical ketones 12 with 1a/4 runs regioselectively in the thermodynamical sense using 1a/12 in excess and yields the enol ethers 13t.The course of this reaction is discussed briefly.
THE MANNICH REACTION OF CARBONYL COMPOUNDS VIA SILYL ENOL ETHERS BY A COMBINATION OF CHLOROIODOMETHANE AND N,N,N',N'-TETRAMETHYLDIAMINOMETHANE
Miyano, Sotaro,Hokari, Hiroshi,Mori, Akira,Hashimoto, Harukichi
, p. 1213 - 1214 (2007/10/02)
The Mannich dimethylaminomethylation of carbonyl compounds is conveniently carried out via trimethylsilyl enol ethers by a combination of chloroiodomethane and N,N,N',N'-tetramethyldiaminomethane in DMSO or DMF as the solvent at ambient temperature.
