Rhodium fluoroapatite (RhFAP) is an efficient catalyst for conjugateaddition of organoboron reagents to α,β-unsaturated carbonyl compounds. A variety of arylboronic acids and α,β-unsaturated carbonyl compounds were converted to the corresponding conjugate-addition products, demonstrating the versatility of the reaction. The reaction is highlyselective. RhFAP was recovered quantitatively by simple filtration
Cobalt(II)-Catalyzed 1,4-Addition of Organoboronic Acids to Activated Alkenes: An Application to Highly<i>cis</i>-Stereoselective Synthesis of Aminoindane Carboxylic Acid Derivatives
It all adds up: The 1,4‐addition of organoboronicacids to activatedalkenes catalyzed by [Co(dppe)Cl2] is described. A [3+2]‐annulation reaction of ortho‐iminoarylboronic acids with acrylates to give various aminoindanecarboxylicacidderivatives with cis‐stereoselectivity is also demonstrated (see scheme; dppe=1,2‐bis(diphenylphosphino)ethane).
[Ru(p-cymene)Cl2]2-catalyzed 1,4-addition reactions between arylboronic acids and butyl acrylate and acrylamide in the presence of phenols were investigated, good to excellent yields were obtained. The addition of phenols remarkably promoted the protonolysis and inhibited the β-H elimination of the 1,4-addition intermediates, and also efficiently suppressed the protonolysis of arylboronic acids.