Modulating Catalytic Selectivity by Base Addition in Aqueous Reductive Amination of 1,6-Hexanediol Using Ru/C

Gupta, NK and Palenicek, P and Nortmeyer, L and Meyer, GM and Schäfer, T and Hellmann, T and Hofmann, JP and Rose, M (2022) Modulating Catalytic Selectivity by Base Addition in Aqueous Reductive Amination of 1,6-Hexanediol Using Ru/C. In: ACS Sustainable Chemistry and Engineering .

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Abstract

Efficient base-modulated product selectivity in the aqueous-phase Ru/C-catalyzed reductive amination of 1,6-hexanediol (HDO) was reported by performing the reaction at mild conditions (463 K, 25 bar H2). High selectivity of amines could be controlled by the addition of different bases; for example, Cs2CO3 addition gave a high yield of 6-amino-1-hexanol (AH, 26). However, the addition of Ba(OH)2 resulted in the formation of high yield of secondary amination products, hexamethylenediamine (HMDA, 34) and azepane (26). The hydroxide base, especially Ba(OH)2, aids in the initial conversion of HDO to AH by significantly decreasing the apparent activation energy from 68 to 48 kJ mol-1. A closer analysis of the formation of secondary products (azepane and HMDA) revealed a faster reaction between NH3 and the carbonyl-containing intermediate by the addition of Ba(OH)2 into the reaction solution.

Item Type:	Journal Article
Publication:	ACS Sustainable Chemistry and Engineering
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society.
Keywords:	Activation energy; Addition reactions; Amines; Ammonia; Barium compounds; Cesium compounds; Reaction intermediates, 1,6-hexanediol; Aqueous phase reactions; Aqueous phasis; Azepanes; Base addition; Base effect; Higher yield; Product selectivities; Reductive amination; Ru-supported carbon, Carbon
Department/Centre:	Division of Mechanical Sciences > Centre for Sustainable Technologies (formerly ASTRA)
Date Deposited:	20 Nov 2022 07:16
Last Modified:	20 Nov 2022 07:16
URI:	https://eprints.iisc.ac.in/id/eprint/77903

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