Transition Metal Ions as Efficient Catalysts for Facile Ortho-Formylation of Phenols under Vilsmeier–Haack Conditions

Table 1

Metal-ion mediated formylation of phenol with Vilsmeier–Haack reagent.

(a)  

S. N	Substrate	Products^a,b	Cu(II)		Ni(II)		Co(II)
			Time (h)	Yield (%)	Time (h)	Yield (%)	Time (h)	Yield (%)
1			10	80	10	82	10	85
2			18	70	16	75	18	70
3			10	80	10	80	12	78
4			12	78	12	80	12	75
5			16	65	18	60	16	60
6			18	72	16	78	18	75
7			16	70	16	72	16	70
8			12	78	12	75	12	75
9			10	82	10	82	10	80
10			10	70	10	65	10	65

^aAll the products were characterized by usual spectral and analytical methods.
^bIsolated yields.

(b)  

S. N	Substrate	Products^a,b	Cd(II)		Zn(II)
			Time (h)	Yield (%)	Time (h)	Yield (%)
1			10	78	12	75
2			16	80	16	75
3			10	80	10	78
4			12	78	12	75
5			16	60	16	55
6			18	70	18	70
7			16	65	16	70
8			12	75	12	75
9			10	80	10	78
10			10	65	10	60

^aAll the products were characterized by usual spectral and analytical methods.
^bIsolated yields.