Palladium complex in a room temperature ionic liquid: a convenient recyclable reagent for catalytic oxidation

Figures & data

Scheme 1. Synthesis of Palladium complexes.

Scheme 2. Catalytic Oxidation for alcohols in EMIM ionic liquid.

Figure 1. Study on the rate of the oxidation reaction of Benzyl alcohol.

Table 1. Oxidation of benzylalcohol to benzaldehyde^a in EMIM–NaOCl system.

Entry	Reaction time (min)	% Conversion
1	40	90.1
2^b	360	<10
3^c	360	NR^d
5^e	40	29.9
6^f	40	48.2

Notes: ^aUnless otherwise indicated, all reactions were carried out with 1 mmol of benzyl alcohol with 0.02 mmol of PdL catalyst, 1 mmol of NaOCl; ^bThe reaction was carried out under oxygen instead of NaOCl; ^cReaction without catalyst; ^dNR: No reaction; ^e0.01 mmol of catalyst; ^f0.5 mmol of NaOCl.

Table 2. Oxidation of alcohols catalyzed by Pd(II) complexes.^a

Entry	Alcohols	Product	Time (min)	% Conversion^b	% Yield^c
1			40	90	85
2			45	98	92
3			40	89	88
4			50	86	84
5			40	86	86
6			40	95	87
7			40	90	86
8			45	86	84
9			40	91	80
10			30	84	79
11			45	96	85
12			60	76	768
13			60	100	964
14			60	68	55

Notes: ^a1 mmol alcohol, 1 mmol NaOCl, 0.02 mmol PdL1, 1 mL (Emim) PF₆-CH₂Cl₂, RT; ^bGC conversion, average of three trials; ^cIsolated yields.

Figure 2. Effect of recycling on conversion.

Scheme 3. Effect of Recycling and reuse of EMIM ionic liquid-catalyst mixture.