Abstract
A pair of enantioselective switchable bifunctional catalysts are shown to promote a range of conjugate addition reactions in up to 95:5 e.r. and 95% conversion. Each catalyst can be switched OFF using conditions that switch the other catalyst ON. Catalyst ON:OFF ratios of up to 98:2 and 1:99 were achieved, with a ratio of reaction rates of up to 16:1 between the ON and OFF states, maintained over complete ON-OFF-ON and OFF-ON-OFF cycles. However, simultaneous operation of the catalyst pair in the same reaction vessel, which in principle could allow product handedness to be switched by simple E-Z isomerisation of the catalyst pair, was unsuccessful. In this first generation complementary pair of enantioselective switchable organocatalysts, the OFF state of one catalyst inhibits the ON state of the other.
| Original language | English |
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| Pages (from-to) | 7077-7081 |
| Number of pages | 5 |
| Journal | Chemical Science |
| Volume | 8 |
| Issue number | 10 |
| Early online date | 23 Aug 2017 |
| DOIs | |
| Publication status | Published - 2017 |