Synthesis 2023; 55(15): 2361-2369
DOI: 10.1055/a-2085-5256
paper
Special Issue dedicated to Prof. David A. Evans

Asymmetric Transfer Hydrogenation of Heterocyclic Compounds in Continuous Flow Using an Immobilized Chiral Phosphoric Acid as the Catalyst

Oleksii Zhelavskyi
,
Yin-Jia Jhang
,
Pavel Nagorny
These studies have been supported by the National Science Foundation (NSF) (Grant No. CHE-1955069).


This manuscript is dedicated to Professor David A. Evans.

Abstract

This manuscript describes transfer hydrogenation of bicyclic nitrogen-containing heterocyclic compounds using the immobilized chiral phosphoric acid catalyst (R)-PS-AdTRIP in batch and continuous flow. A significant improvement in enantioselectivities is achieved in continuous flow with a fluidized bed reactor packed with (R)-PS-AdTRIP when the flow rate is increased from 0.2 mL/min to 2.0–2.5 mL/min. The optimized continuous flow conditions consistently provide 4–6% ee higher selectivity than transfer hydrogenation in batch with 2 mol% of (R)-PS-AdTRIP, and are used to generate multiple chiral products with the same fluidized bed reactor.

Supporting Information



Publication History

Received: 11 March 2023

Accepted after revision: 03 May 2023

Accepted Manuscript online:
03 May 2023

Article published online:
29 June 2023

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