Synthesis and Evaluation of 5-Phenyl-1H-1,4-benzodiazepin-2(3H)-one-Based Palladium Complexes as Precatalysts in C-C Bond Forming Reactions

详细信息    查看全文

• 作者：John Spencer ; David P. Sharratt ; Jairton Dupont ; Adriano L. Monteiro ; Vinicius I. Reis ; Marcelo P. Stracke ; Frank Rominger ; and Iain M. McDonald
• 刊名：Organometallics
• 出版年：2005
• 出版时间：November 7, 2005
• 年：2005
• 卷：24
• 期：23
• 页码：5665 - 5672
• 全文大小：176K
• 年卷期：v.24,no.23(November 7, 2005)
• ISSN：1520-6041

文摘

The C-H activation of C-3-unsubstituted 1,4-benzodiazepin-2(3H)-ones (LH = 2a-c) (2a= 1-methyl-5-phenyl-1H-1,4-benzodiazepin-2(3H)-one, 2b = 1-benzyl-5-phenyl-1H-1,4-benzodiazepin-2(3H)-one, 2c = benzyl-2-(2,3-dihydro-2-oxo-5-phenyl-1,4-benzodiazepin-1-yl)acetate) with Na₂PdCl₄ afforded the insoluble palladacycles [(L)PdCl]₂ 3a-c. Treatment ofthe latter with triphenylphosphine afforded the soluble monomeric triphenylphosphineanalogues [(L)Pd(PPh₃)Cl] 4a-c. 1-Methyl-3-(2-(methylthio)ethyl)-5-phenyl-1H-1,4-benzodiazepin-2(3H)-one (LH = 2d) reacted with Na₂PdCl₄ or with PdCl₂(MeCN)₂ to afford themonomeric cis-S-N-coordinated complex 5d of the type [(LH)PdCl₂]. 3-((tert-Butylthio)methyl)-1-methyl-5-phenyl-1H-1,4-benzodiazepin-2(3H)-one, 2e, reacted with Pd(OAc)₂ inacetic acid and, following LiCl metathesis, yielded the monomeric cis-S-N-bound pincerpalladacycle 6f. X-ray structures of 5d and 4a have been determined. 3a and 6f were foundto be effective precatalysts for Suzuki coupling reactions, and 3a, 3c, and 4a were effectiveprecatalysts in Heck couplings across a range of substrates.