Catalytic 1,4-Selective Hydrosilylation of Pyridines and Benzannulated Congeners
作者:C. David F. Königs、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/anie.201305028
日期:2013.9.16
The hydrosilylation of pyridines and quinolines is strictly 1,4‐selective and likely involves an ionic one‐step rather than the established radical two‐step hydride transfer from a ruthenium(II) hydride complex onto the respective pyridinium and quinolinium ion intermediates (see scheme; ArF=3,5‐(CF3)2C6H3). Even 4‐substituted substrates react highly regioselectively. Isoquinolines yield the 1,2‐reduced
根本不同!吡啶和喹啉的氢化硅烷化严格是1,4-选择性的,可能涉及离子一步法,而不是既定的自由基二步法将氢化物从氢化钌(II)转移到相应的吡啶鎓和喹啉鎓离子中间体上(参见方案) ; Ar F= 3,5-(CF 3)2 C 6 H 3)。甚至4个被取代的底物也具有高度区域选择性的反应。异喹啉可生成1,2还原的杂环。
Selective Silylative Reduction of Pyridines Leading to Structurally Diverse Azacyclic Compounds with the Formation of sp<sup>3</sup> C–Si Bonds
Tris(pentafluorophenyl)borane-catalyzed silylative reduction of pyridines has been developed giving rise to the formation of sp(3) C-Si bonds selectively beta to the nitrogen atom of azacyclic products. Depending on the position and nature of pyridine substituents, structurally diverse azacycles are obtained with high selectivity under the borane catalysis. Mechanistic studies elucidated the sequence