54221-50-0Relevant academic research and scientific papers
New Iridium Catalysts for the Selective Alkylation of Amines by Alcohols under Mild Conditions and for the Synthesis of Quinolines by Acceptor-less Dehydrogenative Condensation
Ruch, Susanne,Irrgang, Torsten,Kempe, Rhett
, p. 13279 - 13285 (2016/02/19)
A novel family of iridium catalysts stabilised by P,N-ligands have been introduced. The ligands are based on imidazo[1,5-b]pyridazin-7-amines and can be synthesised with a broad variety of substitution patterns. The catalysts were synthesised quantitatively from the protonated ligands and a commercially available iridium precursor. The catalysts mediate the alkylation of amines by alcohols under mild conditions (70 °C). In addition, the synthesis of quinolines from secondary or primary alcohols and amino alcohols is reported. This sustainable synthesis proceeds through the liberation of two equivalents of water and two equivalents of dihydrogen. The investigations indicate that catalysts suitable for hydrogen autotransfer or borrowing hydrogen chemistry might also be suitable for acceptor-less dehydrogenative condensation reactions. Your H or mine? A family of catalysts that mediate the alkylation of amines by alcohols under mild conditions are introduced (see scheme; HA=hydrogen autotransfer, BH=borrowing hydrogen, ADC=acceptor-less dehydrogenative condensation). The efficient synthesis of quinolines from alcohols and amino alcohols through the liberation of two equivalents of dihydrogen is also mediated by this catalyst family.
