的二氧化硅负载的三脚架triarylphosphane(二氧化硅-3P-TPP),含tripodally固定在二氧化硅表面上的三苯基膦型铁芯,使得铑和铱催化的C(SP 3) ħ酰胺,脲和烷基吡啶衍生物的borylations。对三脚架膦对铑配合物的配位行为的31 P CP / MAS NMR研究表明,每个膦烷中心都有效地被隔离,从而允许与金属中心进行独立的单P配位。
A silica‐supportedtripodtriarylphosphane (Silica‐3p‐TPP), containing a triphenylphosphane‐type core tripodally immobilized on the silica surface, allows rhodium‐ and iridium‐catalyzedC(sp3)Hborylations of amide, urea and alkylpyridine derivatives. The 31P CP/MAS NMR studies for the coordination behavior of the tripod phosphane towards a rhodium complex indicate efficient site isolation of the
的二氧化硅负载的三脚架triarylphosphane(二氧化硅-3P-TPP),含tripodally固定在二氧化硅表面上的三苯基膦型铁芯,使得铑和铱催化的C(SP 3) ħ酰胺,脲和烷基吡啶衍生物的borylations。对三脚架膦对铑配合物的配位行为的31 P CP / MAS NMR研究表明,每个膦烷中心都有效地被隔离,从而允许与金属中心进行独立的单P配位。
Iridium-Catalyzed Asymmetric Borylation of Unactivated Methylene C(sp<sup>3</sup>)–H Bonds
作者:Ronald L. Reyes、Tomohiro Iwai、Satoshi Maeda、Masaya Sawamura
DOI:10.1021/jacs.9b01952
日期:2019.5.1
Herein, we show the highly enantioselective borylation of unactivated methylene C(sp3)-Hbonds in 2-alkylpyridines and 2-alkyl-1,3-azole derivatives using an iridium-BINOL-based chiral monophosphite catalyst system. Quantum chemical calculations using the artificial force induced reaction (AFIR) method suggested that a monophosphite-Ir-tris(boryl) complex generates a narrow chiral reaction pocket where