111661-02-0Relevant articles and documents
Phosphine catalyzed aldol reaction between ketene silyl acetals and aldehydes: Nucleophilic O-Si and C-Si bond cleavage by phosphines
Matsukawa, Satoru,Okano, Naoko,Imamoto, Tsuneo
, p. 103 - 107 (2000)
A highly nucleophilic phosphine, tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP), catalyzes the aldol reaction between ketene silyl acetals and aldehydes to give the corresponding aldol products in good to high yields. This reaction is considered to proceed through naked enolates produced by nucleophilic O-Si and C-Si bond cleavage.
Practical aldol reaction of trimethylsilyl enolate with aldehyde catalyzed by N-methylimidazole as a Lewis base catalyst
Hagiwara, Hisahiro,Inoguchi, Hideyuki,Fukushima, Masakazu,Hoshi, Takashi,Suzuki, Toshio
, p. 5371 - 5373 (2006)
Aldol reaction of trimethylsilyl enolate with aldehyde proceeded in the presence of a catalytic amount of a Lewis base, N-methylimidazole, and lithium chloride in DMF at room temperature. Not only aryl aldehyde but also alkyl aldehyde provided the aldol p
Mukaiyama Aldol Reactions of Silyl Enolates Catalyzed by Iodine
Phukan, Prodeep
, p. 1065 - 1070 (2004)
Iodine catalyzed Mukaiyama aldol reaction of silyl enol ethers and silyl ketene acetal with aldehydes, ketones and acetals in good yield with preferential antiselectivity has been described.
Lanthanide trifluoromethanesulfonates as reusable catalysts: Aldol reactions in organic solvents
Kobayashi,Hachiya,Takahori
, p. 371 - 373 (1993)
The aldol reaction of silyl enolates with aldehydes or acetals using a lanthanide trifluoromethanesulfonate as catalyst smoothly proceed in organic solvents to afford the corresponding aldol-type adducts in high yields. The catalyst can be easily recovere
A catalytic aldol reaction between ketene silyl acetals and aldehydes promoted by lithium amide under non-acidic conditions
Fujisawa, Hidehiko,Mukaiyama, Teruaki
, p. 182 - 183 (2002)
A catalytic aldol reaction between trimethylsilyl enol ethers and aldehydes by using lithium diphenylamide, a Lewis base catalyst, in DMF or pyridine solvent proceeded smoothly to afford the corresponding aldols under mild conditions.
Enantioselective aldol reaction with bromofluoroketene silyl acetals
Iseki, Katsuhiko,Kuroki, Yoshichika,Kobayashi, Yoshiro
, p. 2225 - 2236 (1999)
The aldol reaction of aldehydes with bromofluoroketene ethyl trimethylsilyl acetal in the presence of a catalytic amount of a chiral Lewis acid at -78°C provides a mixture of the corresponding syn- and anti-α- bromo-α-fluoro-β-hydroxy esters with high enantioselectivities (up to 99% ee). Reaction temperature has a great influence on the stereoselectivity. The aldol reaction at -20°C proceeds with high enantio- and diastereoselectivities to preferentially afford the anti-aldols having opposite signs of optical rotation to those at -78°C.
Bis-zirconium and bis-hafnium catalysts for the strong activation of carbonyl substrates
Hanawa, Hideo,Kii, Satoshi,Asao, Naoki,Maruoka, Keiji
, p. 5543 - 5546 (2000)
(3,3'-Di-t-butyl-5,5'-dimethylbenzophenone-2,2'- dioxy)bis(triisopropoxyzirconium) and its hafnium derivative can be successfully utilized in organic synthesis as bimetallic Lewis acid catalysts. The high activation ability of such catalysts toward carbonyls is emphasized using several synthetic examples including the asymmetric allylation in comparison with the corresponding mono-Zr as well as bis-Ti catalysts. (C) 2000 Elsevier Science Ltd.
Fluorous surface-active distannoxane catalysts
Orita, Akihiro,Tanabe, Shoko,Ono, Tatsuhiko,Otera, Junzo
, p. 1419 - 1423 (2010)
Fluorous distannoxanes (XR2fSnOSnR2 fX)2·nH2O (Rf= C 6F13C2H4) (1: X= C8F 17SO3, n= 10; 4: X = Cl, n=
Lithium pyrrolidone catalyzed aldol reaction between aldehyde and trimethylsilyl enolate
Fujisawa, Hidehiko,Mukaiyama, Teruaki
, p. 858 - 859 (2002)
Lithium pyrrolidone catalyzed aldol reaction between trimethylsilyl enolates and aldehydes proceeded smoothly in a DMF or pyridine solvent to afford the corresponding aldols under weakly basic conditions.
Copper-catalyzed diastereoselective synthesis of β-boryl-α-quaternary carbon carboxylic esters
Zuo, Ya-Jie,Zhong, Zhuoran,Fan, Yinkun,Li, Xiangyu,Chen, Xiaolu,Chang, Yuwei,Song, Ruihu,Fu, Xinpeng,Zhang, Anling,Zhong, Chong-Min
, p. 9237 - 9242 (2018)
Cu(i)-Catalyzed diastereoselective carboboration of α-alkyl-substituted α,β-unsaturated carboxylic esters to produce β-boryl-α-quaternary carbon esters was developed. The carbon skeletons of dialkyl sulfates, primary allyl halides, and benzyl bromides were transferred to the α-position of the substrates to provide products in moderate to good yields with a diastereoselectivity of >95% in most cases. Substrates bearing a β-(hetero)aryl substituent gave higher diastereoselectivities than those bearing a linear β-alkyl substituent. The crystal structure of the potassium trifluoroborate derivative shows that the reactions probably go through a copper(i) enolate intermediate and the diastereoselectivity arises from the electrophilic attack of electrophiles to the less hindered side of the enolates.
Organotin perfluorooctanesulfonates as air-stable Lewis acid catalysts: Synthesis, characterization, and catalysis
An, De Lie,Peng, Zhihong,Orita, Akihiro,Kurita, Akinobu,Man-E, Sumiyo,Ohkubo, Kei,Li, Xingshu,Fukuzumi, Shunichi,Otera, Junzo
, p. 1642 - 1647 (2006)
The reactions of 1,3-dichloro-1,1,3,3-tetrabutyldistannoxane and di-alkyltin dihalides with silver perfluoro-octanesulfonate provided the corresponding sulfonates as hydrates. The number of water molecules (n) of hydration was dependent on the conditions. The distannoxane derivative was identified as n from 0.5 to 6, while in the hydrated mononuclear species and DMSO complexes n varied widely from 4 to 13. 119Sn NMR spectroscopy and conductivity measurements indicated the ionic dissociation of these compounds in solution. These compounds exhibited unusually high solubility in polar organic solvents. The ionic dissociation together with facile hydration probably causes the unusual solubility. The Lewis acidity of these compounds was found to be high among organotin derivatives on the basis of ESR spectra of Superoxide/ metal-ion complexes. In contrast to well-known organotin Inflates, these compounds suffered no hydrolysis upon storage in open air. The high catalytic activity of the distannoxane 1 was exemplified for various carboncarbon bond-forming reactions, such as Mukaiyama-aldol as well as -Michael reactions and allylation of aldehydes.
An air-stable, storable chiral zirconium catalyst for asymmetric aldol reactions
Kobayashi, Shue,Saito, Susumu,Ueno, Masaharu,Yamashita, Yasuhiro
, p. 2016 - 2017 (2003)
Asymmetric aldol reactions of ketene silyl acetals with aldehydes using an air-stable, storable chiral zirconium catalyst, which could be stored for at least 13 weeks at room temperature, proceeded smoothly to afford the desired adducts in high yields wit
Product-catalyzed aldol reaction between trimethylsilyl enolates and aldehydes
Fujisawa, Hidehiko,Nakagawa, Takashi,Mukaiyama, Teruaki
, p. 1241 - 1246 (2004)
Aldol reactions between trimethylsilyl ketene acetals and aldehydes by using a catalytic amount of alkoxide anion proceeded smoothly to afford the corresponding aldols in DMF, indicating that the initially-formed aldolate anion effectively worked to catal
(μ-Hydroxo)-platinum complex-catalyzed enantioselective aldol reaction of aldehydes with 1-methoxy-2-methyl-1-(trimethylsilyloxy)propene in DMF
Kiyooka, Syun-ichi,Matsumoto, Satoshi,Kojima, Masafumi,Sakonaka, Kazuyuki,Maeda, Hirofumi
, p. 1589 - 1592 (2008)
[((R)-BINAP)Pt(μ-OH)]2·2OTf catalyzed the enantioselective aldol reaction of aldehydes with 1-methoxy-2-methyl-(1-trimethylsilyloxy)propene at room temperature in dry DMF in high yields with enantioselectivity up to 92%. This is a versatile exa
Chain propagation determines the chemo- And regioselectivity of alkyl radical additions to C-O: Vs. C-C double bonds
Paulisch, Tiffany O.,Strieth-Kalthoff, Felix,Henkel, Christian,Pitzer, Lena,Guldi, Dirk M.,Glorius, Frank
, p. 731 - 736 (2020/02/03)
Investigations into the selectivity of intermolecular alkyl radical additions to C-O- vs. C-C-double bonds in α,β-unsaturated carbonyl compounds are described. Therefore, a photoredox-initiated radical chain reaction is explored, where the activation of the carbonyl-group through an in situ generated Lewis acid-originating from the substrate-enables the formation of either C-O or the C-C-addition products. α,β-Unsaturated aldehydes form selectively 1,2-, while esters and ketones form the corresponding 1,4-addition products exclusively. Computational studies lead to reason that this chemo- and regioselectivity is determined by the consecutive step, i.e. an electron transfer, after reversible radical addition, which eventually propagates the radical chain.
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.
