Iridium‐Catalysed Reductive Deoxygenation of Ketones with Formic Acid as Traceless Hydride Donor
作者:Zhiheng Yang、Xueya Zhu、Shiyi Yang、Weiyan Cheng、Xiaojian Zhang、Zhanhui Yang
DOI:10.1002/adsc.202000821
日期:2020.12.8
An iridium‐catalysed deoxygenation of ketones and aldehydes is achieved, with formic acid as hydride donor and water as co‐solvent. At low catalyst loading, a number of 4‐(N,N‐disubstituted amino) arylketones are readily deoxygenated in excellent yields and chemoselectivity. Numerous functional groups, especially phenolic and alcoholic hydroxyls, secondary amine, carboxylic acid, and alkyl chloride
以甲酸为氢化物供体,水为助溶剂,实现了铱催化的酮和醛的脱氧。在低催化剂负载下,许多4-(N,N-二取代氨基)芳基酮易于脱氧,具有出色的收率和化学选择性。许多官能团,尤其是酚羟基和醇羟基,仲胺,羧酸和烷基氯,都具有良好的耐受性。当使用DCO 2 D和D 2 O代替它们的氢化对应物时,可获得双歧化的双链烷烃达90%。激活4‐(N,N已证明二取代氨基)芳基会经历各种有用的转化。脱氧氘已用于制备氘代药物分子Chlorambucil-4,4- d 2。
Effective dehydrogenation of 2-pyridylmethanol derivatives catalyzed by an iron complex
An unprecedented iron complex-catalyzed dehydrogenation of alcohols was achieved using CpFe(CO)2Cl with a base or CpFe(CO)(Py)(Ph) as a catalyst without sacrificing the hydrogen acceptors. This reaction effectively (up to TON 67,000) converted 2-pyridylmethanol derivatives to the corresponding ketones or aldehydes. The mechanistic study is also discussed.
Synthesis of Fluorescent 1,3-Diarylated Imidazo[1,5-<i>a</i>]pyridines: Oxidative Condensation−Cyclization of Aryl-2-Pyridylmethylamines and Aldehydes with Elemental Sulfur as an Oxidant
Oxidative condensation−cyclization of aldehydes and aryl-2-pyridylmethylamines proceeded in the presence of a stoichiometric amount of elemental sulfur as an oxidant in the absence of catalyst. The reaction gave a variety of 1,3-diarylated imidazo[1,5-a]pyridines in good to high yields. The products showed fluorescence emission in a wavelength range of 454−524 nm. The quantum yields of 1,3-diarylated
醛和芳基-2-吡啶基甲胺的氧化缩合环化反应在存在化学计算量的元素硫作为氧化剂且没有催化剂的情况下进行。反应以良好至高收率得到各种1,3-二芳基咪唑并[1,5- a ]吡啶。产品显示出在454-524 nm波长范围内的荧光发射。与母体3-单取代的化合物相比,1,3-二芳基咪唑并吡啶的量子产率大大提高。
HOEGBERG, T.;ULFF, B.;RENYI, A. L.;ROSS, S. B., J. MED. CHEM., 1981, 24, N 12, 1499-1507