213843-90-4Relevant academic research and scientific papers
Influence of phosphoramidites in copper-catalyzed conjugate borylation reaction
Sole, Cristina,Bonet, Amadeu,De Vries, Andre H. M.,De Vries, Johannes G.,Lefort, Laurent,Gulyas, Henrik,Fernandez, Elena
, p. 7855 - 7861 (2013/01/16)
Copper(I) has become the preferred metal to catalyze the β-boration of α,β-unsaturated carbonyl compounds, and now we demonstrate that easily accessible monodentate chiral ligands, such as phosphoramidites and phosphites, can be convenient alternative ligands to induce asymmetry in the enantioselective version of this reaction, particularly in the β-boration of α,β-unsaturated imines.
Preparation and characterization of new C2- and C 1-symmetric nitrogen, oxygen, phosphorous, and sulfur derivatives and analogs of TADDOL. part II
Pichota, Arkadius,Gramlich, Volker,Bichsel, Hans-Ulrich,Styner, Thomas,Knoepfel, Thomas,Wuensch, Ralf,Hintermann, Tobias,Schweizer, W. Bernd,Beck, Albert K.,Seebach, Dieter
experimental part, p. 1273 - 1302 (2012/10/07)
TADDOL (=α,α,α′,α′-Tetraaryl-1,3- dioxolane-4,5-dimethanol) and the corresponding dichloride are converted to TADDAMINs (=(4S,5S)-2,2,N,N′-tetramethyl-α,α,α′, α′-tetraphenyl-1,3-dioxolan-4,5-dimethanamines) (Scheme 2) and ureas, 12-15, and to TADDOP derivatives with seven-membered O-P-O ester rings (Schemes 3 and 4). Cl/P-Replacement via the Michaelis-Arbuzov reaction (Scheme 7) on mono- and dichlorides, derived from TADDOL, are described. It was not possible to obtain phosphines with the P-atom attached to the benzhydrylic C-atom of the TADDOL skeleton (Schemes 6 and 7). The X-ray crystal structures (Figs. 1 and 2) of ten of the more than 30 new TADDOL derivatives are discussed. Full experimental details are presented. Copyright
Enantioselective synthesis of Indolizidines bearing quaternary substituted stereocenters via rhodium-catalyzed [2 + 2 + 2] cycloaddition of alkenyl Isocyanates and terminal alkynes
Lee, Ernest E.,Rovis, Tomislav
supporting information; body text, p. 1231 - 1234 (2009/04/07)
An enantioselective synthesis of Indolizidines bearing quaternary substituted stereocenters by way of a rhodium-catalyzed [2 + 2 + 2] cycloaddition of substituted alkenyl Isocyanates and terminal alkynes Is described. The reaction provides lactam products using aliphatic alkynes, whereas aryl alkynes give rise to vlnylogous amide products. Through modification of the phosphoramldlte llgand, high levels of enantloselectlvlty, regloselectlvlty, and product selectivity are obtained for both products.
Development, mechanism, and scope of the palladium-catalyzed enantioselective allene diboration
Burks, Heather E.,Liu, Shubin,Morken, James P.
, p. 8766 - 8773 (2008/02/12)
In the presence of a chiral phosphoramidite ligand, the palladium-catalyzed diboration of allenes can be executed with high enantioselectivity. This reaction provides high levels of selectivity with a range of aromatic and aliphatic allene substrates. Iso
On the role of PIII ligands in the conjugate addition of diorganozinc derivatives to enones
Pfretzschner, Tatjana,Kleemann, Lutz,Janza, Birgit,Harms, Klaus,Schrader, Thomas
, p. 6048 - 6057 (2007/10/03)
A mechanistic study on the conjugate addition of diethylzinc to cyclohexenone catalyzed by various chiral PIII ligands, provides new insights into its mechanism. Complete in situ conversion of the catalytic amount of Cu(OTf)2 into Cu
Synthesis and application of chiral phosphorus ligands derived from TADDOL for the asymmetric conjugate addition of diethyl zinc to enones
Alexakis, Alexandre,Burton, Jonathan,Vastra, Johann,Benhaim, Cyril,Fournioux, Xavier,Van Den Heuvel, Alexandra,Leveque, Jean-Marc,Maze, Frederique,Rosset, Stephane
, p. 4011 - 4027 (2007/10/03)
Asymmetric conjugate addition of diethylzinc to cyclohexen-2-one, chalcone, and benzalacetone has been found to occur with 0.5% copper(II) triflate and 1% chiral phosphite. Cyclic phosphites derived from TADDOL gave excellent to moderate enantiomeric exce
