Nickel-catalyzed coupling reaction of lithium organoborates and aryl mesylates possessing an electron withdrawing group
作者:Yuichi Kobayashi、Ryo Mizojiri
DOI:10.1016/0040-4039(96)01984-3
日期:1996.11
In the presence of NiCl2(PPh3)2 as catalyst, p-methoxycarbonylphenyl mesylate (5) and tosylate (6) react with lithium arylborates 4 (Ar = 2-furyl, Ph, p-Me-Ph; p-Me-Ph) at room temperature to afford the coupling products in high yields. Similarly, mesylates 9–11 coupled with these borates 4 efficiently.
Scope and limitation of the nickel-catalyzed coupling reaction between lithium borates and mesylates
作者:Yuichi Kobayashi、Anthony D. William、Ryo Mizojiri
DOI:10.1016/s0022-328x(02)01174-9
日期:2002.7
Coupling reaction of aryl borates and mesylates derived from phenols and enols was studied. Mesylates with an electron-withdrawing group or ring were highly reactive at room temperature in the presence of NiCl2(PPh3)(2) to furnish the coupling products in good yields. (C) 2002 Elsevier Science B.V. All rights reserved.
Arylation of 8-Acetoxyoctalenone in a Nickel-Catalyzed Coupling Reaction with Lithium Arylborates
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.
Realization of high regioselectivity in the coupling reaction of a cyclopentadiene monoepoxide equivalent and aryl nucleophiles
作者:Yuichi Kobayashi、Eisuke Takahisa、Shahid B. Usmani
DOI:10.1016/s0040-4039(97)10654-2
日期:1998.2
Coupling reaction of monoacetate 2 and aryl hard nucleophiles is realized for the first time, which consists of the lithium arylborates as hard nucleophiles and NiCl2(PPh3)(2) as a catalyst. More importantly, the independent effects of t-BuCN and NaI and their synergistic function are discovered to increase regioselectivity furnishing trans 1,3-isomers 6 as the major products. (C) 1998 Elsevier Science Ltd. All rights reserved.