A cationic iridium complex [Ir(cod)2]SbF6 was found to be a new and efficient Lewis acid catalyst for Mukaiyama aldol and Mannich reactions. Aldehydes react smoothly with silyl enol ethers to give β-siloxy ketones in the presence of 0.5 mol % of [Ir(cod)2]SbF6. The reaction of N-alkyl arylaldimines with ketene silyl acetals in the presence of 5 mol % [Ir(cod)2]SbF6/P(OPh)3 gave β-amino esters. After
Synthesis of Cage‐Shaped Borates Bearing Pyrenylmethyl Groups: Efficient Lewis Acid Catalyst for Photoactivated Glycosylations Driven by Intramolecular Excimer Formation
groups was synthesized. The obtained 3aB functioned as a photoactivated Lewis acid catalyst. The photoactivation originates from the deformation of the cage-shaped scaffold driven by intramolecularexcimerformations of the pyrenes, allowing the catalytic O-glycosylation using glycosyl fluorides to proceed with a high efficiency.
合成了具有芘基甲基的笼形硼酸盐3a B 。得到的3a B 起光活化路易斯酸催化剂的作用。光活化源于由芘的分子内准分子形成驱动的笼形支架的变形,从而允许使用糖基氟化物的催化O-糖基化以高效率进行。