Smith Samantha A M, Lagaditis Paraskevi O, Lüpke Anne, Lough Alan J, Morris Robert H
Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, M5S3H6, Canada.
Department of Chemistry, Johannes Gutenberg University, Mainz, Saarstraße 21, 55122, Mainz, Germany.
Chemistry. 2017 May 29;23(30):7212-7216. doi: 10.1002/chem.201701254. Epub 2017 May 5.
The reductive amination of α-dialkylphosphine acetaldehydes with enantiopure β-aminophosphines is a new, versatile route to unsymmetrical tridentate (pincer) ligands P-NH-P'. Four new ligands PR CH CH NHCHR'CHR''PPh (R=iPr, Cy, R'=Ph, CH(CH ) , R''=Ph, H) prepared in this way are used to make the iron(II) complexes mer-FeCl (CO)(P-NH-P') and mer-FeCl(H)(CO)(P-NH-P'). The hydride complex with the rigid ligand with R'=R''=Ph is an efficient and highly enantioselective homogeneous asymmetric pressure hydrogenation (APH) catalyst. Prochiral aryl ketones are reduced under mild conditions (THF, 0.1 mol % catalyst, 1 mol % KOtBu, 5-10 bar, 50 °C) to the (S)-alcohols, usually in enantiomeric excess (ee) greater than 90 %. DFT calculations provided transition-state structures for the enantiodetermining hydride-transfer step.
用对映体纯的β-氨基膦对α-二烷基膦乙醛进行还原胺化反应，是一种合成不对称三齿（钳形）配体P-NH-P'的新颖且通用的方法。通过这种方法制备的四个新配体PR CH CH NHCHR'CHR''PPh（R = iPr、Cy，R' = Ph、CH(CH ) ，R'' = Ph、H）被用于制备铁（II）配合物mer-FeCl (CO)(P-NH-P')和mer-FeCl(H)(CO)(P-NH-P')。具有刚性配体（R' = R'' = Ph）的氢化物配合物是一种高效且高度对映选择性的均相不对称压力氢化（APH）催化剂。在温和条件下（四氢呋喃，0.1 mol%催化剂，1 mol%叔丁醇钾，5 - 10 巴，50 °C），前手性芳基酮被还原为（S）-醇，对映体过量（ee）通常大于90%。密度泛函理论计算给出了对映体决定的氢化物转移步骤的过渡态结构。
