Ionic-Liquid-Mediated MacMillan’s Catalyst for Diels-Alder Reaction

Table 4

Recyclability of MacMillan’s imidazolidinone catalyst 1/[bmim][NTf₂] system.

No. of cycles	Yield (%)^a	endo : 𝑒𝑥𝑜^b	ee (%)^c
(1)	98	19 : 1	97
(2)	97	19 : 1	97
(3)	94	19 : 1	97
(4)	92	19 : 1	96
(5)	90	17 : 1	97
(6)	92	17 : 1	95

^aIsolated yield, ^bendo : exo ratio was determined by ¹HNMR crude reaction product, ^cee% or was determined by HPLC.