A mild and efficient Dakin reaction mediated by lipase

Figures & data

Scheme 1. A mild and effective Dakin reaction mediated by lipase.

Table 1. The effect of enzyme source on the lipase-mediated Dakin reaction^a.

Entry	Enzyme	Yield (%)
1	ANL (Lipase from Aspergillus niger)	76
2	CalB (Candida antarctica lipase B)	84
3	PSL (Lipase from Pseudomonas sp.)	7
4	PPL (Porcine pancreatic lipase)	6
5	Novozym 435^b	96
6	denatured Novozym 435^c	5
7	No enzyme	5
8	mCPBA	53

^aReaction condition: salicylaldehyde (1 mmol), EA (1 mL), UHP (1.2 mmol), enzyme (300 U), room temperature, 0.5 h.

^bCommercial immobilized CalB.

^cNovozym 435 was denatured by heating it to 100°C for 12 h in water.

Figure 1. The effect of enzyme dosage on the lipase-mediated Dakin reaction.

Note: Reaction condition: salicylaldehyde (1 mmol), EA (1 mL), UHP (1.2 mmol), Novozym 435, room temperature, 0.5 h.

Figure 2. The effect of UHP on the lipase-mediated Dakin reaction.

Note: Reaction condition: salicylaldehyde (1 mmol), EA (1 mL), Novozym 435 (300 U), room temperature, 0.5 h.

Figure 3. The time course of the lipase-mediated Dakin reaction.

Note: Reaction condition: salicylaldehyde (50 mmol), EA (50 mL), UHP (60 mmol), Novozym 435 (15,000 U), room temperature.

Figure 4. The reusability of Novozym 435 in the Dakin reaction.

Note: Reaction condition: salicylaldehyde (1 mmol), EA (1 mL), UHP (1.2 mmol), Novozym 435 (300 U), room temperature, 0.5 h.

Table 2. Lipase-mediated Dakin reaction with various hydroxylated benzaldehydes

Entry	Hydroxylated benzaldehyde	Yield (%)
1		96
2		91
3		96
4		94
5		93
6		90
7		97
8		97
9		95
10		93

Note: Reaction condition: hydroxylated benzaldehyde (1 mmol), EA (5 mL), UHP (1.5 mmol), Novozym 435 (300 U), room temperature, 0.5 h.