*2.3. Organocatalytic Activity*

First, the organocatalytic activity of camphor-derived phase-transfer organocatalysts **I**–**IX** was tested in electrophilic functionalizations of β-keto ester **9** (Scheme 3). Details of the optimization reactions can be found in the Supporting Information. The asymmetric α-fluorination of β-keto ester **9** with *N*-fluorobenzenesulfonimide (NFSI) proceeded under complete conversion and gave the product **10** with low enantioselectivity (87% yield and up to 29% ee). The best result was obtained with the catalyst **VIII** in toluene in the presence of K3PO4. In contrast, up to 86% ee has been reported in the literature for the α-fluorination of β-keto ester **9** with NFSI [15,32]. Similarly, the α-chlorination of **9** with *N*-chlorosuccinimide (NCI) gave product **11** in complete conversion and a meager 7% ee when squaramide PTC **IX** was used (for comparison, up to 80% ee has been reported in the literature when using alternative catalyst scaffolds [33]). Disappointingly, both the α-hydroxylation [34] of **9** with tosylimine **12**/H2O2 and the ring opening of arylaziridine **14** [35] with **9** did not give the expected products **13** and **16**, respectively. In both cases, no conversion was observed. Finally, the asymmetric Michael addition of glycine Schiff base **16** to methyl acrylate (**17**) was investigated, with up to 90% ee reported in the literature [36]. Catalyst **V** gave the expected product **18** with full conversion but low enantioselectivity (11% ee).

**Scheme 3.** Organocatalytic activity of camphor-derived phase-transfer organocatalysts; MTBE: methyl *tert*-butyl ether.
