| Autor: |
von Grotthuss, Esther, Prey, Sven E., Bolte, Michael, Lerner, Hans‐Wolfram, Wagner, Matthias |
| Předmět: |
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| Zdroj: |
Angewandte Chemie International Edition; Dec2018, Vol. 57 Issue 50, p16491-16495, 5p |
| Abstrakt: |
Alkali metal salts M2[1] (M=Li, Na) of doubly reduced 9,10‐dimethyl‐9,10‐dihydro‐9,10‐diboraanthracene (1) instantaneously add the C=O bond of CO2 across their boron centers to furnish formal [4+2]‐cycloadducts M2[2]. If only 1 equiv of CO2 is supplied, these products are stable. In the presence of excess CO2, however, C−O bond cleavage occurs and an O2− equivalent is transferred to CO2 to furnish CO and [CO3]2−. With M=Li, Li2CO3 precipitates and the neutral 1 is liberated such that it can be reduced again to establish a catalytic cycle. With M=Na, [CO3]2− remains coordinated to both boron atoms in a bridging mode (Na2[4]). A mechanistic scenario is proposed, based on isolated intermediates and model reactions. Two in one sweep: A doubly reduced 9,10‐diboraanthracene splits CO2 quantitatively and under ambient conditions to give CO and carbonate ions. If lithium metal is used as the reducing agent, Li2CO3 precipitates from the reaction mixture and the CO2 reduction process becomes catalytic. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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