Is water a suitable solvent for the catalytic amination of alcohols?

Abstract

The catalytic conversion of biomass and biogenic platform chemicals typically requires the use of solvents. Water is present already in the raw materials and in most cases a suitable solvent for the typically highly polar substrates. Hence, the development of novel catalytic routes for further processing would profit from the optimization of the reaction conditions in the aqueous phase mainly for energetic reasons by avoiding the initial water separation. Herein, we report the amination of biogenic alcohols in aqueous solutions using solid Ru-based catalysts and ammonia as a reactant. The influence of diff erent support materials and bimetallic catalysts is investigated for the amination of isomannide as a biogenic diol. Most importantly, the transferability of the reaction conditions to various other primary and secondary alcohols is successfully proved. Hence, water appears to be a suitable solvent for the sustainable production of biogenic amines and off ers great potential for further process development.

Sustainable Routes for the Synthesis of Renewable Heteroatom-Containing Chemicals

“…Inspired by the naturally occurring aldolase enzyme, the direct reductive aminolysis of glucose toward several short-chained amines with carbon yields up to 87% have been achieved. , Likewise, the amination of isomannide, a renewable sugar-derivative, in water using a heterogeneous ruthenium catalyst has been demonstrated. This process can be extended to the conversion of other biogenic alcohols such as ethanol or hexane-1,6-diol …”

Effective synthesis of 5-amino-1-pentanol by reductive amination of biomass-derived 2-hydroxytetrahydropyran over supported Ni catalysts

“…Due to the readily available alcohols from not only the coal and petroleum industry but also renewable biomass, the direct amination of alcohols has been developed for the production of primary amines in recent years [2,4,[10][11][12]. The direct amination of alcohols is widely considered to be proceeded by the borrowing hydrogen mechanism (BH, Scheme 1), and water is generated as the main byproduct [2,4,[10][11][12][13]. Nonetheless, this process generally requires high reaction temperatures in the range of 150-250 °C, owing to the dehydrogenation of C-OH over metal catalysts usually occurred at a high temperature (Scheme 1, Step 1) [2].…”

Amino-polystyrene supported hexaethylene glycol-bridged ionic liquid as an efficient heterogeneous catalyst for water-mediated nucleophilic hydroxylation

“…14,15 In addition to the low cost of water and its availability and nontoxic nature, its high polarity, ability to form hydrogen bonding networks, high specic heat capacity, high cohesive energy, and large surface tension signicantly inuence organic conversions. [16][17][18] A diverse range of biologically relevant molecules contain the hydroxyl group, and thus, alcohols constitute important synthetic targets in the pharmaceutical eld. While the synthesis of alcohols from alkyl halides by nucleophilic substitution has a long history, 19 simple replacement of halogens by water is difficult due to its poor nucleophilicity under mild alkaline conditions.…”