trans-[RuCl2(phosphane)2(1,2-diamine)] and Chiraltrans-[RuCl2(diphosphane)(1,2-diamine)]: Shelf-Stable Precatalysts for the Rapid, Productive, and Stereoselective Hydrogenation of Ketones
摘要:
A turnover number (TON) of 2 400 000 and a turnover frequency (TOF) of 63 s-1 are achieved with the chiral RuII complex 1 (R=p-CH3 C6 H4 ) in the asymmetric hydrogenation of acetophenone. Carbonyl-selective asymmetric hydrogenation of α,β-unsaturated ketones proceeds in the presence of these RuII catalysts, and 4-substituted cyclohexanones are selectively converted into cis alcohols.
Selective Hydrogenation of Benzophenones to Benzhydrols. Asymmetric Synthesis of Unsymmetrical Diarylmethanols
摘要:
[GRAPHICS]trans-RuCl2[P(C6H4-4-CH3)(3)](2)(NH2CH2CH2NH2) acts as a highly effective precatalyst for the hydrogenation of a variety of benzophenone derivatives to benzhydrols that proceeds smoothly at 8 atm and 23-35 degrees C in 2-propanol containing t-C4H9OK with a substrate/catalyst ratio of 2000-20000. Use of a BINAP/chiral diamine Ru complex effects asymmetric hydrogenation of various ortho-substituted benzophenones and benzoylferrocene to chiral diarylmethanols with consistently high ee.