Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
Department of Chemistry, Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28/II, 8010, Graz, Austria.
ChemSusChem. 2022 Sep 20;15(18):e202200914. doi: 10.1002/cssc.202200914. Epub 2022 Aug 1.
Cyclic primary amines are elementary building blocks to many fine chemicals, pharmaceuticals, and polymers. Here, a powerful one-pot Raney Ni-based catalytic strategy was developed to transform guaiacol into cyclohexylamine using NH (7 bar) and H (10 bar) in up to 94 % yield. The methodology was extendable to the conversion of a wider range of guaiacols and syringols into their corresponding cyclohexylamines. Notably, a crude bio-oil originating from the reductive catalytic fractionation of birch lignocellulose was transformed into a product mixture rich in 4-propylcyclohexylamine, constituting an interesting case of catalytic funneling. The isolated yield of the desired 4-propylcyclohexylamine reached as high as 7 wt % (on lignin basis). Preliminary mechanistic studies pointed at the consecutive occurrence of three key catalytic transformations, namely, demethoxylation, hydrogenation, and amination.
环状伯胺是许多精细化学品、药物和聚合物的基本组成部分。在这里，开发了一种强大的一锅法雷尼镍基催化策略，可在高达 94%的收率下，使用 NH（7 巴）和 H（10 巴）将愈创木酚转化为环己胺。该方法可扩展至将更广泛范围的愈创木酚和丁香酚转化为相应的环己胺。值得注意的是，源自桦木木质纤维素还原催化分馏的粗生物油被转化为富含 4-丙基环己胺的产物混合物，这构成了催化漏斗的一个有趣案例。所需的 4-丙基环己胺的分离收率高达 7 wt%（基于木质素）。初步的机理研究表明，连续发生了三个关键的催化转化，即脱甲氧基化、加氢和胺化。
