6397-70-2Relevant academic research and scientific papers
Asymmetric carbon-carbon bond forming reactions catalysed by metal(II) bis(oxazoline) complexes immobilized using supported ionic liquids
Goodrich,Hardacre,Paun,Ribeiro,Kennedy,Lourenco,Manyar,De Castro, C. A. Nieto,Besnea,Parvulescu
, p. 995 - 1004 (2011)
A series of bis(oxazoline) metal(II) complexes has been supported on silica and carbon supports by non-covalent immobilisation using an ionic liquid. The catalytic performance of these solids was compared for the enantioselective Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene and the Mukaiyama-aldol reaction between methyl pyruvate and 1-methoxy-1- trimethylsilyloxypropene. In both reactions the enantioselectivity was strongly influenced by the choice of support displaying enantioselectivies (ee values) up to 40% higher than those conducted under homogeneous reaction conditions.
Efficient α-chlorination of carbonyl containing compounds under basic conditions using methyl chlorosulfate
Silva, Saúl,Maycock, Christopher D.
supporting information, p. 1233 - 1238 (2018/02/27)
An efficient method for the α-chlorination of ketones under basic conditions is described using methyl chlorosulfate. Its applicability for the chlorination of other functional groups has also been studied and it is equally useful for the synthesis of α-chloroesters and amides. Methyl chlorosulfate is described for the first time as a positive chlorine source. Some aldol reactions which occur during the chlorination of some substrates are also reported.
Unprecedented alkylation of silicon enolates with alcohols via carbenium ion formations catalyzed by tin hydroxide-embedded montmorillonite
Tandiary, Michael Andreas,Asano, Masashi,Hattori, Taiki,Takehira, Satoshi,Masui, Yoichi,Onaka, Makoto
supporting information, p. 1925 - 1928 (2017/04/27)
The solid acid, tin hydroxide-embedded montmorillonite, catalyzes the unprecedented alkylation of various silicon enolates with primary, secondary and tertiary benzylic alcohols as well as secondary allylic alcohols. The acid catalysis of Sn-Mont was not only higher than that of the other ion-exchanged montmorillonites (M-Mont; M?=?H, Ti, Fe and Al), but also higher than that of the typical homogeneous acid catalysts such as BF3·OEt2, TMSOTf and TfOH.
Isopropylmagnesium chloride-promoted unilateral addition of Grignard reagents to β-diketones: One-pot syntheses of β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones
Yuan, Rui,Zhao, Dan,Zhang, Li-Yuan,Pan, Xiang,Yang, Yan,Wang, Pei,Li, Hong-Feng,Da, Chao-Shan
supporting information, p. 724 - 728 (2016/01/12)
The regioselective unilateral additions of Grignard reagents to acyclic or cyclic β-diketones were effectively promoted by sub-stoichiometric amounts of i-PrMgCl to afford β-tertiary hydroxyl ketones or 3-substituted cyclic-2-enones, respectively. Also, the addition of Grignard reagents to acyclic β-diketones followed by a reaction with cyclic β-diketones in a one-pot process was put forward. The reaction mechanism was discussed in detail to explain the high regioselectivity via chemical experiments, hydrogen-deuterium exchange and mass spectrometry.
One-Pot Synthesis of β,β-Disubstituted α,β-Unsaturated Carbonyl Compounds
Sugiura, Masaharu,Ashikari, Yasuhiko,Nakajima, Makoto
, p. 8830 - 8835 (2015/09/15)
TiCl4-promoted aldol reaction of ketones as aldol acceptors followed by elimination of the titanoxy group from the Ti-aldolates affords β,β-disubstituted α,β-unsaturated carbonyl compounds in a one-pot procedure. The use of additives, such as DMF, N,N,N′,N′-tetramethylethylenediamine, and pyridine, in the elimination step was found to be important.
Mukaiyama aldol reactions catalyzed by a trimeric organo aluminum(III) alkoxide
Kim, So Han,Yoon, Sungwoo,Kim, Youngjo,Verkade, John G.
, p. 1193 - 1206 (2014/09/30)
Mukaiyama aldol reactions of enol ethers with a variety of aldehydes and ketones are efficiently catalyzed at 0-25 °C by the sterically bulky trimeric organo aluminum(III) alkoxide 1 synthesized via the reaction of 3 equiv of AlMe3 with tripodal tris(2-hydroxy-3-tert-butyl-5-methylphenyl) methane and the elimination of 3 equiv of methane. Comparisons of its catalytic properties with the less sterically hindered analogue 2, the more sterically hindered analogue 3, a monomeric aluminum near-analogue 4, and a dimeric alumatrane 5 revealed that 1 possesses superior activity.
The mukaiyama aldol reactions for congested ketones catalyzed by solid acid of tin(IV) ion-exchanged montmorillonite
Takehira, Satoshi,Masui, Yoichi,Onaka, Makoto
supporting information, p. 498 - 500 (2014/04/17)
Tin(IV) ion-exchanged montmorillonite (Sn-Mont) was found to be an excellent solid acid catalyst for the Mukaiyama aldol reactions of congested ketones with silicon enolates from ketones as well as esters. It was disclosed that Sn-Mont was far more active than other metal ion-or proton-exchanged montmorillonites and typical homogeneous acid catalysts such as TMSOTf and BF3?OEt2.
An efficient Cu(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase catalyst for asymmetric carbon-carbon bond formation
Doherty, Simon,Knight, Julian G.,Ellison, Jack R.,Goodrich, Peter,Hall, Leanne,Hardacre, Christopher,Muldoon, Mark J.,Park, Soomin,Ribeiro, Ana,De Castro, Carlos Alberto Nieto,Lourenco, Maria Jose,Davey, Paul
, p. 1470 - 1479 (2014/03/21)
The asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene and the Mukaiyama-aldol reaction between methylpyruvate and 1-phenyl-1-trimethylsilyloxyethene have been catalysed by heterogeneous copper(II)-bis(oxazoline)-based pol
Synthesis of silaoxazolinium salts bearing weakly coordinating anions: Structures and catalytic activities in the aldol reaction
Chandra Sheker Reddy, Anugu,Chen, Zhang,Hatanaka, Tohru,Minami, Tatsuya,Hatanaka, Yasuo
, p. 3575 - 3582 (2013/07/26)
The synthesis and structures of silaoxazolinium salts 2 and their application to the catalytic Mukaiyama aldol reaction are described. The reaction of (N-amidomethyl)dimethylchlorosilane (1a) or (N-amidomethyl) bis(trimethylsilyl)chlorosilane (1b) with me
Sequential one-pot addition of excess aryl-grignard reagents and electrophiles to O-alkyl thioformates
Murai, Toshiaki,Morikawa, Kenta,Maruyama, Toshifumi
, p. 13112 - 13119 (2013/10/01)
The sequential addition of aromatic Grignard reagents to O-alkyl thioformates proceeded to completion within 30s to give aryl benzylic sulfanes in good yields. This reaction may begin with the nucleophilic attack of the Grignard reagent onto the carbon atom of the O-alkyl thioformates, followed by the elimination of ROMgBr to generate aromatic thioaldehydes, which then react with a second molecule of the Grignard reagent at the sulfur atom to form arylsulfanyl benzylic Grignard reagents. To confirm the generation of aromatic thioaldehydes, the reaction between O-alkyl thioformates and phenyl Grignard reagent was carried out in the presence of cyclopentadiene. As a result, hetero-Diels-Alder adducts of the thioaldehyde and the diene were formed. The treatment of a mixture of the thioformate and phenyl Grignard reagent with iodine gave 1,2-bis(phenylsulfanyl)-1,2-diphenyl ethane as a product, which indicated the formation of arylsulfanyl benzylic Grignard reagents in the reaction mixture. When electrophiles were added to the Grignard reagents that were generated insitu, four-component coupling products, that is, O-alkyl thioformates, two molecules of Grignard reagents, and electrophiles, were obtained in moderate-to-good yields. The use of silyl chloride or allylic bromides gave the adducts within 5min, whereas the reaction with benzylic halides required more than 30min. The addition to carbonyl compounds was complete within 1min and the use of lithium bromide as an additive enhanced the yields of the four-component coupling products. Finally, oxiranes and imines also participated in the coupling reaction. Into the melting pot: The addition of excess aryl Grignard reagents and electrophiles to O-alkyl thioformates gives aryl sulfanes through four-component coupling reactions (see scheme). These reactions may involve the formation of aromatic thioaldehydes and aryl-benzylic Grignard reagents as intermediates. For addition to carbonyl compounds, the use of lithium halides as an additive enhanced the efficiency of the reaction. Copyright
