Efficient Alkyl Ether Synthesis via Palladium-Catalyzed, Picolinamide-Directed Alkoxylation of Unactivated C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds at Remote Positions
作者:Shu-Yu Zhang、Gang He、Yingsheng Zhao、Kiwan Wright、William A. Nack、Gong Chen
DOI:10.1021/ja3023972
日期:2012.5.2
functionalization of unactivatedsp(3)- and sp(2)-hybridized C-H bonds. In the Pd(OAc)(2)-catalyzed, PhI(OAc)(2)-mediated reaction system, picolinamide-protected amine substrates undergo facile alkoxylation at the γ or δ positions with a range of alcohols, including t-BuOH, to give alkoxylated products. This method features a relatively broad substrate scope for amines and alcohols, inexpensive reagents
Palladium‐Catalyzed Picolinamide‐Directed Acetoxylation of Unactivated γ‐C(
<i>sp</i>
<sup>3</sup>
)H Bonds of Alkylamines
作者:Qiong Li、Shu‐Yu Zhang、Gang He、William A. Nack、Gong Chen
DOI:10.1002/adsc.201400121
日期:2014.5.5
protocol for palladium‐catalyzedacetoxylation of the γ‐C(sp3)Hbonds of N‐alkylpicolinamide substrates using PhI(OAc)2 oxidant. These reactions involve the use of substoichiometric amounts of Li2CO3 additive, which effectively suppresses the competing intramolecular CH amination process. Under these conditions, N‐propylpicolinamides bearing α substituents can be cleanly converted to γ‐acetoxylated
我们报告的γ-C(钯催化的乙酰氧基化的新协议SP 3) H的键Ñ使用Φ-alkylpicolinamide基板(OAC)2氧化剂。这些反应涉及使用亚化学计量的Li 2 CO 3添加剂,该添加剂可有效抑制竞争的分子内CH胺化过程。在这些条件下,带有α取代基的N-丙基吡啶甲酰胺可以优良的收率干净地转化为γ-乙酰氧基化胺产物。这种CH乙酰氧基化反应也可以与其他Pd催化的吡啶甲酰胺定向C一起使用H功能化反应可快速实现支架的多样化。
Divergent Synthesis of Silicon-Containing Peptides via Pd-Catalyzed Post-Assembly γ-C(sp<sup>3</sup>)–H Silylation
作者:Bei-Bei Zhan、Jun Fan、Liang Jin、Bing-Feng Shi
DOI:10.1021/acscatal.9b00544
日期:2019.4.5
compatibility with a wide range of oligopeptides bearing various α-aminoacid residues render this protocol a valuable strategy to access γ-silyl-α-amino acids and peptides. This reaction enriches the chemical toolbox for the site-specific peptidemodification and showcases the vast potential of postsynthetic diversification of peptidesvia late-stage C(sp3)–H functionalization.