Table 8.

One-pot synthesis of tetrahydrobenzo[b]pyran with aldehyde, malononitrile and dimedone catalyzed by HMS/Pr-PTSC-Cu^a.

Entry	Product	Time (min)	Yield (%)b	TOF (h-1)	M.p (°C)	Ref
1		30	97	7698	209–211	25
2		35	96	6568	198–200	42
3		70	81	2747	176–178	43
4		40	93	5508	210–212	44
5		30	96	7619	228–231	19
6		80	80	2386	194–196	45
7		65	83	3049	210–212	45
8		40	95	5626	226–230	46
9		50	88	4207	205–207	47
10		60	85	3373	230–234	43
11c		15	99	15,714	256–260	48

^aReaction conditions: aldehyde (1 mmol), malononitrile (1 mmol), dimedone (1 mmol), HMS/Pr-PTSC-Cu (0.004 g) in EtOH at room temperature.

^bPure yield.

^cReaction conditions: aldehyde (1 mmol), malononitrile (2 mmol), dimedone (2 mmol), HMS/Pr-PTSC-Cu (0.008 g) in EtOH at room temperature.