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Sustainable Organocatalyzed Enantioselective Catalytic Michael Additions in Betaine-Derived Deep Eutectic Solvents

2023; Georg Thieme Verlag; Volume: 07; Issue: 03 Linguagem: Inglês

10.1055/a-2117-9971

2509-9396

Anthony J. Burke, Daniela Fonseca, Ana Carolina Amorim Orrico, Elisabete P. Carreiro, João P. Prates Ramalho, Gesine J. Hermann, Hans‐Jürgen Federsel, Ana Rita C. Duarte,

Inorganic and Organometallic Chemistry

Abstract The organocatalyst cinchonidine-squaramide was immobilized within three different deep eutectic solvents (DESs): betaine:d-sorbitol:water, betaine: d-xylitol:water, and betaine:d-mannitol:water and evaluated in a well-known asymmetric Michael addition. These reactions provided excellent yields (up to 99%) and enantioselectivities (up to 98%) using only 1 mol% of organocatalyst. It was also possible to achieve 9 cycles in reactions with DES (betaine:d-sorbitol:water), proving the high recyclability of this system. In the reactions realized with only 0.5 mol% of organocatalyst, it was possible to achieve 5 cycles, and the products were obtained with high yields (up to 95%) and excellent enantioselectivities (up to 94%), using DES (betaine:d-sorbitol:water).