Palladium(II)-catalyzed asymmetric cycloisomerization of enynes for axially chiral biaryl construction
摘要:
Palladium(II)-catalyzed asymmetric cycloisomerization of enynes with (R)-binap gave axially chiral biaryls with up to 99%ee. The reactivity and enantioselectivity depended on the nature and position of substituent of the arene ring. The enynes with ortho methoxy arene at alkyne terminus gave chiral biaryls with good enantioselectivity. (C) 2012 Elsevier Ltd. All rights reserved.
The copper(II)-catalyzed (4+1) cyclizations and copper(I)-catalyzed (3+2) cycloadditions of iodonium ylides and alkynes were successfully developed by employing efficient and safe iodonium ylides instead of traditional diazo compounds. Highly functionalized dimethyl (E)-3-benzylideneindoline-2,2-dicarboxylates and methyl 5-(2-hydroxyphenyl)-2-methoxy-4-phenylfuran-3-carboxylates were conveniently prepared