Communications Chemistry

Table 1 Optimization of the reaction conditions^a.

From: Chemoselective cycloisomerization of O-alkenylbenzamides via concomitant 1,2-aryl migration/elimination mediated by hypervalent iodine reagents


Entry	HIR	Solvent	Additive^b	T (^oC)	Yield^c of
Entry	HIR	Solvent	Additive^b	T (^oC)	2a (%)	3a (%)
1	PhIO	MeOH	BF₃▪OEt₂	rt	56	―
2	PhIO	MeOH	Et₃N	rt	NR	―
3	PhIO	MeOH	TFA	rt	61	―
4	PhIO	MeOH	TfOH	rt	63	―
5	PhIO	MeOH	TMSOTf	rt	70	―
6	PhIO	MeOH	LiClO₄	rt	NR	―
7	PhIO	MeOH	50%H₂SO₄	rt	58	―
8	PhIO	MeOH	TMSOTf	Reflux	81	―
9	HTIB	DCE	―	rt	―	44
10	HTIB	DCE	―	80	―	55
11	PhIO	DCE	S1	80	―	54
12	PhIO	DCE	S2	80	―	52
13	PhIO	DCE	S3	80	―	63
14	PhIO	DCE	S4	80	―	69
15^d	PhIO	DCE	S4	80	―	73
16^e	PhIO	DCE	S4	80	―	70
17^f	PhIO	DCE	S4	80	―	90
18^g	PhIO	DCE	S4	80	―	82
19^h	PhIO	DCE	S4	80	―	77
20ⁱ	PhIO	DCE	S4	80	―	90

^aReaction conditions: 1a (0.5 mmol), HIR (1.5 equiv), solvent (5.0 mL), rt. NR = no reaction.
^bEntries 3–12, additives (1.5 equiv) were used; entries 13–20, additives (0.2 equiv) were used.
^cIsolated yield.
^dBF₃▪OEt₂ (1.5 equiv) was added.
^eTMSOTf (1.5 equiv) was added.
^fLiClO₄ (1.5 equiv) was added.
^gZn(ClO₄)₂ (1.5 equiv) was added.
^hLiClO₄ (1.0 equiv) was added.
ⁱLiClO₄ (1.8 equiv) was added. (For details, see Supplementary Table S1 and S2).

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