Table 2. Screening of Conditions for the Trapping of Semibenzenes with Tritylium Cations^a.

entry	X	solvent	5:6 ratio
1	BF4–	CH2Cl2	15:85
2	BF4–	THF	5:95
3	BF4–	toluene	>1:<99
4	BF4–	acetone	10:90
5	BF4–	MeCN	80:20
6	PF6–	MeCN	55:45
7	SnCl5–	MeCN	33:66
8b	BF4–	MeCN	95:5
9c	BF4–	MeCN	95:5
10d	BF4–	MeCN	50:50

^aGeneral reaction conditions, 1f (0.30 mmol, 1.0 equiv), allylMgBr (1.0 M in Et₂O, 0.36 mmol, 1.2 equiv), Pd(PPh₃)₄ (1 mol %), 2-Me-THF (1 mL), 15 min at r.t., then Ph₃CX (0.33 mmol, 1.1 equiv), in the specified solvent, 30 min at r.t.

^bAddition of the dearomatized compound to a solution of the electrophile.

^c1.5 equiv of the electrophile.

^dAt 0 °C.