74532-80-2Relevant academic research and scientific papers
Dual secondary amine/N-heterocyclic carbene catalysis in the asymmetric Michael/cross-benzoin cascade reaction of β-oxo sulfones with enals
Enders, Dieter,Grossmann, Andre,Huang, He,Raabe, Gerhard
supporting information; experimental part, p. 4298 - 4301 (2011/09/16)
Polyfuncionalized cyclopentanones with three contiguous stereogenic centers were formed in good to excellent yields and stereoselectivities by utilizing a secondary amine/N-heterocyclic carbene catalytic system in the reaction of β-oxo sulfones with unsaturated aldehydes. In addition, the influence of the catalysts on the diastereoselectivity of the final product was studied by 1H NMR spectroscopy. The combination secondary amine/N-heterocyclic carbene turned out to be a good dual catalytic system for the reaction of β-oxo sulfones with enals leading to polyfunctionalized cyclopentanones in good to excellent yields and stereoselectivities. Further improvement of the enantiomeric excess is possible by crystallization. Direct observations by NMR spectroscopy revealed that the carbene catalyst alone is triggering the diastereoselectivity.
Investigation of oxacycle formation by base-promoted endo-mode ring-closing reaction of allenes
Kitagaki, Shinji,Kawamura, Takamasa,Shibata, Daisuke,Mukai, Chisato
experimental part, p. 11086 - 11095 (2009/04/11)
The base-promoted endo-mode ring closure of electron-withdrawing group-substituted allenes provided the following interesting results: (1) the endo-mode ring-closing reaction of 1-(benzyloxycarbonyl)-1-(ω-hydroxyalkyl)allenes smoothly proceeded during the
The MARDi cascade: A Michael-initiated domino-multicomponent approach for the stereoselective synthesis of seven-membered rings
Coquerel, Yoann,Filippini, Marie-Helene,Bensa, David,Rodriguez, Jean
scheme or table, p. 3078 - 3092 (2009/04/11)
The MARDi cascade is a recently invented three-component Michael-initiated condensation involving 1,3-dicarbonyl derivatives. It allows regio- and stereocontrolled access to a variety of functionalised and substituted seven-membered rings. The substitutio
A facile one-pot synthesis of β-keto sulfones from ketones under solvent-free conditions
Kumar, Dalip,Sundaree, Swapna,Rao,Varma, Rajender S.
, p. 4197 - 4199 (2007/10/03)
An easy solvent-free method is described for the conversion of ketones into β-keto sulfones in high yields that involves the in situ generation of α-tosyloxyketones, followed by nucleophilic substitution with sodium arene sulfinate in the presence of tetra-butylammonium bromide at room temperature. The salient features of this one-pot protocol are short reaction times, cleaner reaction profiles, and simple work-up that precludes the use of toxic solvents.
Hypervalent iodine in synthesis. 66. One pot preparation of β-keto sulfones by reaction of ketones, [hydroxy(tosyloxy) iodo] benzene, and sodium sulfinates
Xie,Chen
, p. 3145 - 3149 (2007/10/03)
One pot reactions of ketones, [hydroxy(tosyloxy)iodo] benzene and sodium sulfinates lead to the formation of the corresponding β-keto sulfones under mild conditions and in good yield.
Stereoselective Synthesis of a Bicyclic Ketooxetane via a Thionium Ion-Mediated Cyclisation Reaction
Craig, Donald,Lawrence, Ronnie M.,Tapolczay, David J.
, p. 1001 - 1003 (2007/10/03)
The synthesis of a bicyelic ketooxetane using as the key step the ethylaluminium dichloride-mediated cyclisation of a Z-silyl enol ether onto a thionium ion 'trigger' attached to a five-membered carbocyclic template is described. Attempted cyclisation of the analogous substrate possessing a six-membered ring did not afford the oxetane, but instead the product of 1,2-hydride shift. The mechanism of this unexpected transformation was conclusively established by analysis of the products of attempted cyclisation of a deuterium-labelled substrate.
A New Synthesis of Macrocyclic Lactones by Rearrangement of 2-Hydroxyalkyl-2-phenylsulphonylcycloalkanones
Bhat, Venkatramana,Cookson, Richard C.
, p. 1123 - 1124 (2007/10/02)
2-Hydroxyalkyl-2-phenylsulphonylcycloalkanones undergo base-catalysed isomerisation into phenylsulphonyl-lactones with incorporation of the side-chain into the ring.
CHEMOSELECTIVE OXIDATION OF SULFIDES TO SULFONES WITH POTASSIUM HYDROGEN PERSULFATE
Trost, Barry M.,Curran, Dennis P.
, p. 1287 - 1290 (2007/10/02)
Potassium hydrogen persulfate in aqueous methanol was found to be a convenient, inexpensive, and chemoselective reagent for the oxidation of sulfides to sulfones and sulfoxides in the presence of other common functional groups.
