| S. No. | U.S./ Catalyst | R | Temp (˚C) | Time (min) | Yield (%) | M.P. (˚C)rep/M.P. (˚C)lit |
| 1 | U.S./SA-MNPs [22] | m-Br | 40 | 30 | 95 | 302-304/301-303 [22] |
| 2 | U.S./[EMIM]OAc [23] | m-Br | - | - | - | Not reported |
| 3 | U.S./CuFe2O4 | m-Br | R.T. | 30 | 96 (4a) | 300-302/301-303 [22] |
| 4 | U.S./SA-MNPs [22] | p-F | - | - | - | Not reported |
| 5 | U.S./[EMIM]OAc [23] | p-F | - | - | - | Not reported |
| 6 | U.S./CuFe2O4 | p-F | R.T. | 25 | 92 (4b) | 188-190/190(19) |
| 7 | U.S./SA-MNPs [22] | p-CH3 | 40 | 40 | 92 | 187-189/186-188 [22] |
| 8 | U.S./[EMIM]OAc [23] | p-CH3 | - | - | - | Not reported |
| 9 | U.S./CuFe2O4 | p-CH3 | R.T. | 30 | 94 (4e) | 184-186/186-188 [22] |
| 10 | U.S./SA-MNPs [22] | m-NO2 | 40 | 30 | 92 | 268-270/269-271 [22] |
| 11 | U.S./[EMIM]OAc [23] | m-NO2 | R.T. | 90 | 87 | 317-319/313-315 [23] |
| 12 | U.S./CuFe2O4 | m-NO2 | R.T. | 30 | 88 (4c) | 310-312/313-315 [23] |
| 13 | U.S./SA-MNPs [22] | p-NO2 | - | - | - | Not reported |
| 14 | U.S./[EMIM]OAc [23] | p-NO2 | R.T. | 70 | 70 | 239-242/235-238 [23] |
| 15 | U.S./CuFe2O4 | p-NO2 | R.T. | 30 | 86 (4d) | 232-234/235-238 [23] |
| S. Nos. 1-9 contain electron releasing groups where as SNos.10-15 contain electron withdrawing groups on the aldehyde | ||||||