Palladium-Catalyzed Synthesis of 4-Arylcoumarins Using Triarylbismuth Compounds as Atom-Efficient Multicoupling Organometallic Nucleophiles
作者:Maddali L. N. Rao、Varadhachari Venkatesh、Deepak N. Jadhav
DOI:10.1002/ejoc.201000134
日期:——
Triarylbismuth compounds have been cross-coupled as atom-efficientmulticoupling organometallic nucleophiles with 4-bromo- and 4-(trifluoromethylsulfonyloxy)coumarins underpalladiumcatalysis conditions. These reactions afforded an array of 4-arylcoumarins in high yields. The general palladium protocol has been demonstrated to be efficient for the coupling of both bromide and triflate derivatives
Asymmetric Conjugate Reductions of Coumarins. A New Route to Tolterodine and Related Coumarin Derivatives
作者:Brian D. Gallagher、Benjamin R. Taft、Bruce H. Lipshutz
DOI:10.1021/ol9020404
日期:2009.12.3
The combination of catalytic amounts of [(R)-DTBM-SEGPHOS]CuH in the presence of stoichiometric DEMS (diethoxymethylsilane) in toluene at room temperature leads to asymmetric reductions of 4-substituted coumarins. Several targets or their known precursors can be prepared in high yields and ee’s, including the muscarine receptor antagonist (R)-tolterodine.
<scp>Ruthenium‐Catalysed</scp> Asymmetric Intramolecular Isomerization/Esterification Reaction: Direct Synthesis of Chiral Dihydrocoumarins
作者:Lingzi Zhao、Xuchao Wang、Qing Qiang、Xingwei Zhao、Feipeng Liu、Shenci Lu、Zi‐Qiang Rong
DOI:10.1002/cjoc.202400084
日期:——
An asymmetric isomerization/intramolecular coupling reaction of allylic alcohols to synthesize chiral dihydrocoumarins was successfully accomplished through ruthenium catalysis. This method demonstrates a wide substrate applicability, excellent tolerance for various functional groups, and good enantioselectivities (up to 90% ee). It provides a convenient pathway to produce a diverse range of structurally