Evaluation of palladacycles as a non-rhodium based alternative for the asymmetric conjugate 1,4-addition of arylboronic acids to α,β-unsaturated enones

• Main Authors: Wong, Jonathan, Gan, Kennard, Chen, Houguang Jeremy, Pullarkat, Sumod A.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Chemistry::Inorganic chemistry::Synthesis
• Online Access: https://hdl.handle.net/10356/103735; http://hdl.handle.net/10220/24564
• Institution: Nanyang Technological University

The asymmetric conjugate 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds is an extremely versatile and widely used organic transformation. While the rhodium(I)-catalysed reaction has been thoroughly explored, the asymmetric palladium-catalysed protocol is far less developed and understood, particularly with acyclic enones as substrates. Herein, we report the systematic evaluation of a series of metallacycles for this reaction and the conjugate addition of arylboronic acids to a wide range of α,β-unsaturated enones, catalysed by an easily accessible and robust chiral phosphapalladacycle in high yields and enantioselectivities.