二齿吡啶甲酰胺(PA)导向基团可实现新的对映选择性钯(II)催化的胺的苄基CH芳基化反应。该反应提供了烷基胺对映选择性苄基γ-C-H芳基化的第一个实例,并以高达97%的ee进行。2,2'-二羟基-1,1'-联萘(BINOL)磷酸配体Cs 2 CO 3和无溶剂条件对于高对映选择性至关重要。机理研究表明,多个BINOL配体参与立体确定CH palpalation步骤。
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。
Palladium-Catalyzed Picolinamide-Directed Alkylation of Unactivated C(sp<sup>3</sup>)–H Bonds with Alkyl Iodides
作者:Shu-Yu Zhang、Gang He、William A. Nack、Yingsheng Zhao、Qiong Li、Gong Chen
DOI:10.1021/ja312277g
日期:2013.2.13
alkylation of γ-C(sp(3))-H bonds of picolinamide-protected aliphatic amine substrates with primary alkyl iodides via palladium catalysis. Ag(2)CO(3) and dibenzyl phosphate, (BnO)(2)PO(2)H, are critical promoters of this reaction. These reactions provide a convenient and straightforward method for the preparation of high-value N-containing products from readily available amine and alkyl iodide precursors
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.
Ritter reaction for the synthesis of picolinamides
作者:Benedikt S. Schreib、Jacopo Margarini、Erick M. Carreira
DOI:10.1016/j.tet.2022.132937
日期:2022.9
The synthesis of picolinamides through Ritterreaction of 2-cyanopyridine with alcohols and alkenes is reported. Moreover, a range of additional heteroaryl nitriles successfully participate in the amidation reaction. Salient features of the reaction include the operational simplicity and the inexpensive reagents used. The synthetic utility of a camphene derived picolinamide is demonstrated through