Science of Synthesis

Koo, S., Science of Synthesis, (2010) 45, 1407.

Tropylium bromide ‌209‌ (or ‌184‌) reacts as an electrophilic reagent with hetero nucleophiles to give the addition products ‌210‌ (‌Table 2‌).[‌195‌] The reactions with water, hydrogen sulfide, and ammonia in an aqueous medium produce bis(cyclohepta-2,4,6-trienyl) ether, bis(cyclohepta-2,4,6-trienyl) sulfide, and bis(cyclohepta-2,4,6-trienyl)amine, respectively. In the reaction of tropylium cation with water, cyclohepta-2,4,6-trien-1-ol has never been isolated, but only detected as a transient intermediate leading to bis(cyclohepta-2,4,6-trienyl) ether by 1H NMR spectroscopy.[‌196‌] Similarly, it has not been possible to isolate the primary products with hydrogen sulfide and ammonia. The reaction with saturated ethereal ammonia exclusively produces the tertiary amine, tris(cyclohepta-2,4,6-trienyl)amine. Other hetero nucleophiles such as dimethylamine, benzamide, acetamide, succinimide, and potassium cyanide react normally with tropylium bromide (‌209‌) to give 7-substituted cyclohepta-1,3,5-trienes ‌210‌. Tropylium cation can be reduced to 1,1′-bi(cyclohepta-2,4,6-trien-1-yl) almost quantitatively by zinc dust in aqueous solution.[‌195‌] The reaction of tropylium tetrafluoroborate (‌184‌) with sodium carbonate in refluxing acetonitrile produces tropone and cycloheptatriene in a disproportionation sequence (‌Scheme 46‌).[‌197‌]

‌Meeee 8‌ Meeeeeee ee Meeeee Meeeeeeeeeee ee e Meeeeeeee Meee[‌888‌,‌888‌]

Meeeeeeeeee	Meeeeee	Meeeeee	Meeeee (%)	Mee
M8Me	M8M		88	[‌888‌,‌888‌]
M8M	M8M		888	[‌888‌]
MM8	M8M		88	[‌888‌]
MM8	Me8M		88	[‌888‌]
Me8MM	M8M		88e	[‌888‌]
MeMM8	M8M		88	[‌888‌]
MeMM8	eeeeeeee		88	[‌888‌]
eeeeeeeeeee	eeeeeeee		88	[‌888‌]
MMM	M8M		88e	[‌888‌]

e Meeee eeeee.

e Meeeeeeee eeeeeeeeeeeeeeeee (‌888‌) eee eeee.

e Meeeeeee eeeee eeeee eeeeeeeeeeee.

‌Meeeee 88‌ Meeeeee Meeeeeeee ee Meeeeeeee Meeee[‌888‌,‌888‌]

Meeeeeeeeeee ee e eeeeee eeeeeeeee eeeee ee eee eeeeeeeeeeeeeeeee eeeeee eeeeee eee eeeeeeeee ee eeeeeeeeeeeeeeeeee eeeeeeee eeeeeeeeeeeeeeeeeee(8) eeeeeeeee, eeeee eeeeeee eeeeee-eeeee eeeeeeeeeeeee eeeeeeeee eeee eeee eeeeee ee eeeeeeeeeeeeeeeeee.[‌888‌] Meeeee eeeeeeee eee eeeeeee eee ee eeeeeeeeeeee eee eeeeeee eeee eeeeeeeee eeeeeeeeeeeeeeeee (‌888‌) ee eeee 8-eeeeeeeeeee eeeeeeeeee-8,8,8-eeeeeee ‌888‌ (‌Meeeee 88‌). Meeeeeeeeeeeee ee 8-eeeeeeeeeee eeeeeeeeeeeeeeeee ‌888‌ eee 8-eeeeeeeeeee eeeeeeeeeeeeeeeee ‌888‌ eee eeeeeeeeeeee eeeeeeeeee ee eee eeeeeeee eeeeeeeeeee. Mee 8-eeeeeeeeeee eeeeee ‌888‌ eee eee ee eeeeeeee ee eee eeee ee eeeeeeeeeeeee.

‌Meeeee 88‌ Meeeeeee ee Meeeee Meeeeeeeeee ee Meeeeeeee Meeeeeeeeeeeeeeee eee Meeeeeeeee Meeeeeeeeeeeeeeeeeee[‌888‌]

‌Meeeeeeeeee 88‌

M8	Meeee (%) ee ‌888‌	Meeee (%) ee ‌888‌	Meeee (%) ee ‌888‌	Mee
	88	88	88	[‌888‌]
	88	88	88	[‌888‌]
	88	88	–	[‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeeeee-8,8,8-eeeeee-8-eeeeeeeeeeee (‌888‌, Me = MM); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeee eeeee eee ee eeeeeeee eeeeeee eee eeee eee eee eeeeeeeee eeeee.

M eeee ee eeeeeeeee eeeeeee (‌888‌; 8.88 e) ee M8M (8 eM) eee eeeeee eeee e eeee ee MMM (8.88 e) ee M8M (8 eM). Meee eee eeeeeeeee eee eee eee eeeee eeeeeeeee eee eeeeeeeee eeee Me8M (8 × 8 eM). Mee eeeeeeee eeeeeeee eeee eeeee (MeMM8) eee eeeeeeeeeeee ee eeee ee eeeeee eee. Mee eeeee eeeeeee eee eeeeeeee ee eeeeeeeeeee eeeeeeeeeeee; eeeee: 8.88 e (88%).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8e, 888.