One-pot relay reduction–isomerization of β-trifluoromethylated-α,β-unsaturated ketones to chiral β-trifluoromethylated saturated ketones over combined catalysts in aqueous medium
the 4,4,4-trifluorobut-2-en-1-ol system undermetal-freeconditions to afford the corresponding saturated ketones in high to excellent chemical yields using such a convenient and easy-to-handle base as DBU at the toluene refluxing temperature, and utilization of the corresponding optically active substrates unambiguously demonstrated that this transformation proceeded in a highly stereoselective fashion
Rhodium(<scp>i</scp>)-catalyzed 1,4-conjugate arylation toward β-fluoroalkylated electron-deficient alkenes: a new entry to a construction of a tertiary carbon center possessing a fluoroalkyl group
Treatment of β-fluoroalkylated-α,β-unsaturated ketones with 1.2 equiv. of various arylboronic acids in the presence of 5 mol% of [Rh(COD)2]BF4 and 6 mol% of (S)-BINAP in toluene/H2O (v/v = 4/1) at the reflux temperature for 3 h gave the corresponding Michael adducts in high yields with over 90% enantioselectivity. Though other electron-deficient alkenes, such as vinylsulfone and vinylphosphonate, were found to be much less reactive in the rhodium-catalyzed conjugate addition with arylboronic acids, the reaction of various arylstannanes toward such electron-deficient alkenes took place very smoothly to afford the corresponding adducts in high yields.
Treatment of fluoroalkylated electron-deficient olefins with various boronic acids in the presence of a catalytic amount of Rh(l) coordinated with (S)-BINAP in toluene/H2O at the reflux temperature for 3 h gave the corresponding conjugate addition products with high enantioselectivity in high yields. (C) 2008 Elsevier Ltd. All rights reserved.
One-pot relay reduction–isomerization of β-trifluoromethylated-α,β-unsaturated ketones to chiral β-trifluoromethylated saturated ketones over combined catalysts in aqueous medium
作者:Xuelin Xia、Meng Wu、Ronghua Jin、Tanyu Cheng、Guohua Liu
DOI:10.1039/c5gc00479a
日期:——
Combining Ru-functionalized silica and RuCl(PPh3)3 enables one-pot relay reduction-isomerizations of β-CF3-substituted-α,β-unsaturated ketones to chiral saturated ketones.