Pd-Catalyzed, <i>ortho</i> C–H Methylation and Fluorination of Benzaldehydes Using Orthanilic Acids as Transient Directing Groups
作者:Xiao-Yang Chen、Erik J. Sorensen
DOI:10.1021/jacs.8b00048
日期:2018.2.28
using commercially available orthanilic acids as transient directing groups. In these reactions, the 1-fluoro-2,4,6-trimethylpyridinium salts can be either a bystanding F+ oxidant or an electrophilic fluorinating reagent. An X-ray crystal structure of a benzaldehyde ortho C-H palladation intermediate was obtained using triphenylphosphine as the stabilizing ligand.
直接的、Pd 催化的邻位 CH 甲基化和苯甲醛氟化已经使用市售的邻苯甲酸作为瞬时导向基团完成。在这些反应中,1-氟-2,4,6-三甲基吡啶鎓盐可以是旁通的 F+ 氧化剂或亲电子氟化试剂。使用三苯基膦作为稳定配体获得苯甲醛邻位 CH 钯化中间体的 X 射线晶体结构。
Cascade reaction for the synthesis of polycyclic aromatic hydrocarbons via transient directing group strategy
A Pd(II)-catalyzed cascade synthesis of diverse polycyclicaromatichydrocarbons via transient directing group strategy has been developed, involving the consecutive arylation, cyclization and aromatization. The efficiency and practicality were demonstrated by wide substrate range, concise synthetic pathway and mild reaction conditions. The subsequent transformations of the benz[a]anthracene core accessed
已经开发了一种通过Pd(II)催化的通过瞬态导向基团策略级联的多种多环芳烃,涉及连续的芳基化,环化和芳构化。广泛的底物范围,简明的合成途径和温和的反应条件证明了其效率和实用性。苯并[ a ]蒽核心的后续转化获得了天然的生物活性PAH分子。
developed to construct PAHs with diverse shape, width, and edge topology. The precursors of PAHs were obtained by using a direct arylation of arenes via a transient ligand-directed C–H functionalization strategy and the cycloaromatization was readily achieved by using a Brønstedacid catalyst. This novel route provides an opportunity to build up PAHs in a highly efficient manner.