Table 2 Various control experiments to obtain insights into the reaction mechanism.

Reaction conditions: 17 mg of catalyst, 0.33 mmol of benzyl alcohol, 0.2 mmol of Cs2CO3, 330 μl of toluene, O2, 100°C, 2 hours for entries 2 to 7 and 12 hours for entries 1 and 8 to 16, Conversions are an average of at least three runs. n.d., not detected.

EntryCatalystConversion
(%)
Selectivity
(%)*
1CTF-HUST-15>99
2CTF-1-30035>99
3CTF-1-40064>99
4CTF-1-45069>99
5CTF-1-50074>99
6CTF-1-55087>99
7CTF-1-60097>99
8No catalyst<1n.d.
9CTF-1-40099>99
10CTF-1-4003>99
11CTF-1-40011>99
12§CTF-1-40099>99
13||CTF-1-40099>99
14CTF-1-40099>99
15#CTF-1-40026>99
16**CTF-1-4007>99

*Selectivity toward benzaldehyde.

†Under Ar atmosphere.

‡With p-benzoquinone as the superoxide (O2) scavenger.

§With tert-butyl alcohol as the OH scavenger.

||With NaN3 as the 1O2 scavenger.

¶With 1,3-diphenylisobenzofuran as the 1O2 scavenger.

#With ammonium oxalate.

**The reaction was done at room temperature.