Arylation of 8-Acetoxyoctalenone in a Nickel-Catalyzed Coupling Reaction with Lithium Arylborates
摘要:
In order to find a suitable organometallic compound and a catalyst for the arylation of 8-acetoxyoctalenone 4 (a stereoisomeric mixture of 4 alpha and 4 beta), phenylation was first-investigated with PhZnX (7: X = Cl; 8: X = Br)/Pd or Ni cat., PhSnBu3 (9)/Pd cat. and LiCl, and [PhB(Bu)(OCHMeCHMeO)]Li (10a)/Ni cat. Berate 10a provided the desired product 11a with high stereoselectivity. The stereochemical outcome was irrespective of the stereochemistry of the acetoxy group in 4. Four more aryl groups, p-R-C6H4 (R = Me, MeO, Ph, and Me2N), were installed stereoselectively with this method.
Decalin systems with alpha- and beta-allylic alcohol groups have been subjected to the Stork silyl methyl radical cyclisation reaction to introduce a hydroxymethyl function at the angular position.