A one-pot [Bmim]OH-mediated synthesis of 3-benzamidocoumarins
摘要:
The first example of an ionic liquid-promoted one-pot synthesis of 3-benzamidocoumarins from salicylaldehydes and 2-pheny-1,3-oxazolan-5-one via Knoevenagel condensation-ring transformation cascades has been reported. No by-product formation, operational simplicity, ambient temperature and high yield (85-97%) are the salient features of the present synthetic protocol. After isolation of the product, the ionic liquid, [Bmim]OH can be easily recycled for further use without any loss of efficiency. (C) 2009 Elsevier Ltd. All rights reserved.
An asymmetrichydrogenation of 3-benzoylaminocoumarins was achieved for the first time using our BridgePhos-Rh catalytic system, providing chiral 3-amino dihydrocoumarins in high yields (up to 98 %) and with excellent enantioselectivities (up to 99.7 % ee). The relationship between the enantioselectivities of the hydrogenations and the dihedral angles and the resulting π-π stacking effects of the BridgePhos-Rh
A one-pot [Bmim]OH-mediated synthesis of 3-benzamidocoumarins
作者:Lal Dhar S. Yadav、Santosh Singh、Vijai K. Rai
DOI:10.1016/j.tetlet.2009.02.166
日期:2009.5
The first example of an ionic liquid-promoted one-pot synthesis of 3-benzamidocoumarins from salicylaldehydes and 2-pheny-1,3-oxazolan-5-one via Knoevenagel condensation-ring transformation cascades has been reported. No by-product formation, operational simplicity, ambient temperature and high yield (85-97%) are the salient features of the present synthetic protocol. After isolation of the product, the ionic liquid, [Bmim]OH can be easily recycled for further use without any loss of efficiency. (C) 2009 Elsevier Ltd. All rights reserved.