Direct Arylation/Alkylation/Magnesiation of Benzyl Alcohols in the Presence of Grignard Reagents via Ni-, Fe-, or Co-Catalyzed sp<sup>3</sup> C–O Bond Activation
作者:Da-Gang Yu、Xin Wang、Ru-Yi Zhu、Shuang Luo、Xiao-Bo Zhang、Bi-Qin Wang、Lei Wang、Zhang-Jie Shi
DOI:10.1021/ja307045r
日期:2012.9.12
Direct application of benzyl alcohols (or their magnesium salts) as electrophiles in various reactions with Grignardreagents has been developed via transition metal-catalyzed sp(3) C-O bond activation. Ni complex was found to be an efficient catalyst for the first direct cross coupling of benzyl alcohols with aryl/alkyl Grignardreagents, while Fe, Co, or Ni catalysts could promote the unprecedented
已经通过过渡金属催化的 sp(3) CO 键活化开发了苯甲醇(或其镁盐)在与格氏试剂的各种反应中作为亲电试剂的直接应用。发现 Ni 配合物是苯甲醇与芳基/烷基格氏试剂首次直接交叉偶联的有效催化剂,而 Fe、Co 或 Ni 催化剂可以促进苯甲醇在( n) 己基MgCl。这些方法提供了将苯甲醇转化为各种功能的直接途径。
Selective Conversion of Benzylic Phosphates into Diarylmethanes Through Al(OTf)<sub>3</sub>
-Catalyzed Friedel-Crafts-Type Benzylation
Al(OTf)3 exhibits superior catalyst performance in the Friedel–Crafts‐type benzylation using benzylicphosphate as an electrophile. The reaction can be conducted even with 0.2 mol‐% of the catalyst. Twenty‐one different diarylmethanes are formed. The chemoselective property of the catalyst toward the phosphate group over acetate and bromide is noteworthy.
1,3-Dicyclohexylimidazol-2-ylidene as a Superior Ligand for the Nickel-Catalyzed Cross-Couplings of Aryl and Benzyl Methyl Ethers with Organoboron Reagents
A new catalytic system has been developed involving the use of Ni(cod)2 in conjunction with 1,3-dicyclohexylimidazol-2-ylidene for the cross-coupling of aryl and benzyl methyl ethers with organoboron reagents. This method not only allows for the use of readily available methyl ethers as halide surrogates but also provides a functional group tolerant method for the late-stage derivatization of complex molecules.