Chiral Phosphoric Acid-Catalyzed Enantioselective and Diastereoselective Spiroketalizations
摘要:
Catalytic enantioselective and diastereoselective spiroketalizations with BINOL-derived chiral phosphoric acids are reported. The chiral catalyst can override the inherent preference for the formation of thermodynamic spiroketals, and highly selective formation of nonthermodynamic spiroketals could be achieved under the reaction conditions.
Pd<sup>II</sup>-Catalyzed Spiroketalization of Ketoallylic Diols
作者:Jean A. Palmes、Paulo H. S. Paioti、Leonardo Perez de Souza、Aaron Aponick
DOI:10.1002/chem.201301723
日期:2013.8.26
at 0 °C, these dehydrative cyclization reactions require only mild conditions to produce vinyl‐substituted spiroketals in high yields after brief reaction times with water as the only byproduct. Using this method, the stereochemical information embedded at the nucleophile is transmitted “down‐the‐chain” and efficiently sets the stereochemistry at both the anomeric carbon atom and the newly formed allylic