876944-91-1Relevant academic research and scientific papers
Diastereo- and enantioselective hydrogenative aldol coupling of vinyl ketones: Design of effective monodentate TADDOL-like phosphonite ligands
Bee, Cisco,Soo, Bong Han,Hassan, Abbas,Iida, Hiroki,Krische, Michael J.
, p. 2746 - 2747 (2008)
We report the first enantioselective reductive aldol couplings of vinyl ketones, which were achieved through the design of a novel monodentate TADDOL-like phosphonite ligand. Specifically, hydrogenation of commercially available methyl vinyl ketone (MVK) or ethyl vinyl ketone (EVK) in the presence of aldehydes 1a-7a using cationic rhodium catalysts modified by chiral TADDOL-like phosphonite ligands AP-I and AP-IV produces aldol adducts 1b-7b and 1c-7c with excellent control of relative and absolute stereochemistry. The absolute stereochemical assignments of the aldol adducts are made in analogy to that determined for the 5-bromophthalimido derivative of aldol adduct 1b and the 2-bromo-5-nitrobenzoate of 3b, which were established by single-crystal X-ray diffraction analysis using the anomalous dispersion method. Copyright
