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Please login to access the full content or check if you have access via45.22.2.1.9.1 Method 1: Lewis Acid Catalyzed Cyclodehydrogenation of Hexaarylbenzenes
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Chang, C.-S.; Wu, Y.-T., Science of Synthesis, (2010) 45, 992.
In the presence of Lewis acids, hexaarylbenzenes 150 and 152 undergo oxidative intramolecular cyclodehydrogenation to form hexabenzocoronenes 151 and 153, respectively (Scheme 43). Hexabenzo[bc,ef,hi,kl,no,qr]coronene (151, R1 = H) was first prepared by treatment with an aluminum trichloride/sodium chloride melt at high temperature.[107] This protocol sometimes gives partially cyclodehydrogenated products:[108] the mechanism of this reaction is, therefore, believed to involve a stepwise cyclodehydrogenation with subsequent aromatization. Combinations of copper(II) salts and aluminum trichloride in inert solvents are the most efficient reagents for these cyclodehydrogenation reactions, which even occur at room temperature.[108] Iron(III) chloride is also an efficient catalyst for the reaction:[109] cyclodehydrogenation of the hexadodecyl derivative 150 [R1 = (CH2)11Me] with iron(III) chloride[110] gives a better yield of the corresponding hexabenzocoronene (77%) than do combinations of copper(II) salts and aluminum trichloride (49%).[111] For cyclodehydrogenation of hexaphenylbenzene (150, R1 = H), molybdenum(V) chloride may be a superior reagent to iron(III) chloride or to combinations of aluminum trichloride and copper(II) chloride, but chlorinated derivatives of 151 are also formed.[112]
Me eee eeee ee eeeee-eeeeeeeeeee eeeeeeeeeeeeeeee, eee eeeeeeeeeeeeeeeeeeee eeeeeeee eeee eeeeeeee eeeeeeeeeee, e eeeeee Meeee eeee, eee eeeee eeeeeeee ee eeeeeeeee ee eee eeeee eeeeeeeeeeee ee eee eeeeeeeee. Me eeeee eeeee, eeeeeeeeeeeee ee eee eeeeeeeeee eee eeeeeeeee, eee eee eee ee eeee(MMM) eeeeeeee, e eeeeee eeee, eeeeee eeee eeeeeeeee eeeeeee.[888,888]
Me eeeeeeee, eee eeee-eeee-eeeee eeeeeeeeee 888 (M8 = e-Me) eee ee eeeeeeee eeeeeeee ee e eee-eee eeeeeeee eeee eeeeeeeeeeeeeeeee eee eeee-eeeee eeeeeeee ee 88% eeeee ee eeeee eeee(MMM) eeeeeeee ee eeee eee Meeee eeee eeeeeeee eee eee eeeeeee.[888] Meeeeee-eeeeeeeeeee eeeeeeeee[ee,ee,ee,ee,ee,ee]eeeeeeeee eeeeeee eee eeeeeeeeeee ee eeeeeee eeeeeeeeeeeeeeeee eeeeeeeee, eeee ee eeeeeeeee, eeeeeeeee, ee eeeeeeeeeeee.[888,888]
Meeeee 88 Meeeeeeee[ee,ee,ee,ee,ee,ee]eeeeeeee eee Mee Meeeeeeeeee[888–888]
M8 | Meeeeeeeee | Meeeee (%) | Mee |
---|---|---|---|
M | MeMe8, MeMe, 888–888°M, 8.8 e | 8 | [888] |
M | MeMe8, MeMe8, MM8, 88°M, 88 e | 88 | [888] |
M | MeMe8, MM8Me8, 88°M, 88 e | <88.8e | [888] |
e-Me | MeMe8, MM8Me8, 88°M, 88 e | 88 | [888] |
e-Me | MeMe8, e-MeMe, MM8Me8, MeMM8 | 88e | [888] |
(MM8)88Me | Me(MMe)8, MeMe8, MM8, 88°M | 88 | [888] |
(MM8)88Me | MeMe8, MeMM8, MM8Me8, ee, 88 eee | 88 | [888] |
(MM8)8MMMe(MM8)8eMe | MeMe8, MeMM8, MM8Me8, ee, 88 eee | 88 | [888] |
8-MM8M8 | MeMe8, MeMM8, MM8Me8, MM8, ee, 8.8 e | 88 | [888] |
e e.e. = eee eeeeeeee.
e Meeee eeeeeeeeee ee MMMM eeeeeeee.
e Mee-eee eeeeeeee ee eeeeeeeeeeeeeeeee eee e-MeMe; e.e. M8 = M ee eeeeeeee eeeeeeee.
M8 | M8 | M8 | M8 | Meee (eee) | Meeee (%) | Mee |
---|---|---|---|---|---|---|
Me | (MM8)88Me | (MM8)88Me | (MM8)88Me | 88 | 88 | [888] |
Me | Me | (MM8)88Me | (MM8)88Me | 88 | 88 | [888] |
Me | (MM8)88Me | (MM8)88Me | Me | 88 | 88 | [888] |
M | M | (MM8)88Me | (MM8)88Me | 88 | 88 | [888] |
Meeeeeeeeeee Meeeeeeee
Meeeeeeee[ee,ee,ee,ee,ee,ee]eeeeeeee (888, M8 = M):[888]
MMMMMMM: Meeeeeee eeeeeeeeeee eeee ee e eeeeee eeeeeeee ee eee eeeeeee eee eeeeee eeeeeeeee eeee eeeee.
MMMMMMM: Meeeee eeeeeeeee ee eeeeeeeee eeeeeeeee, eee eeeee ee eeeeeeeeee, eeee eeeeeeeeee, eee eeeeeeeee.
M eeeeeee ee MeMe8 (8.88 e, 88.8 eeee), MeMe8 (8.88 e, 88.8 eeee), eeeeeeeeeeeeeeeee (888, M8 = M; 8.88 e, 8.88 eeee), eee MM8 (888 eM) eee eeeeeee ee ee eeeee eeeee eee ~88 e. Mee eeeeeeee eee eeeeeeee ee eee eeeeeeee ee MeMM (888 eM), eee eee eeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeee eeeeeeeeeeee eeee M8M, eeeee MMe, M8M, eeeee ee MM8, M8M, eeeeeee, MM8, eee MM8Me8 (~888 eM ee eeeee eeeeeeee), eee eeee eeeee eeeee eeeeee ee eeee eee eeeee eeeeeee; eeeee: 8.8 e (88%). Meee eee eeeeeee eeeeeeee ee eeeeeeeeeee eeee e eeeeeeeeeee eeeeeeee eeee 888 ee 888°M eeee e eeeee ee 8 ee ee 8 × 88−8 Meee; ee >888°M.
8,8,8,88,88,88-Meee-eeee-eeeeeeeeeeeeee[ee,ee,ee,ee,ee,ee]eeeeeeee (888, M8 = e-Me):[888]
MMMMMMM: Meeeeeeeeeee ee eeeeeeeee, e eeeee- eee eeee-eeeeeeeee eeeeeeeee, eee ee eee, eeee, eee eeeeeeeeeee eeeee eeeeeeee.
M eee eeeee ee e eeeee eeee ee MeMe8 (88.8 e, 888 eeee) ee MeMM8 (888 eM) eeee eeeee ee e eeeeeee ee eeeeeeeeeeeeeeeee (8.8 e, 8 eeee), e-MeMe (8.8 eM, 88 eeee), eee eeeee MM8Me8 (888 eM), eee eee eeeeeeeee eeeeeeeeee eee eeeeee ee 88°M eee 8 e eeeee eeeee eee eeeeeee eeeeeee eee eeee. Mee eeeeeee eee eeee eeeeee ee ee, eee eee eeeeeeeee MeMe8 eeee eee eeeee eeeeeeee eeee 88 eee. Mee eeee eee eeee eee eeeeeee eee 8 e ee ee eee eeee eeeeee eeee MeMM (888 eM). Mee eeeeee eeeeeeeeeee eee eeeeeeeee ee eeeeeeeeee eee eeeeee eeee eeee MeMM (8 × 88 eM). Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:8); eeeee: 8.88 e (88%); ee >888°M (eeeeee).
References
[107] | Meeeeee, M.; Meeeee, M. M.; Meee, M. M. M., Meee. Meee. Meee, (8888) 88, 8888. |
[108] | Müeee, M.; Meeeeeee, M.; Meeeeeeee, M.; Meeeee, M.; Müeeee, M., M. Meeee. Meee., (8888) 88, 888. |
[109] | Meeeee, M. M.; Meeeeeeee, M.; Meeeeee, M.; Müeeee, M., Meee.–Mee. M., (8888) 8, 8888. |
[110] | Meeee, M. M.; Meeeeee, M.; Meeee, M. M.; Müeeee, M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
[111] | Meeeee, M.; Meeeee, M.; Müeeee, M.; Meee, M. M., Meeee. Meee., (8888) 888, 8888; Meeee. Meee. Mee. Me. Meee., (8888) 88, 8888. |
[112] | Meeeeee, M.; Meeeeíe, M.; Meee, M. M., M. Mee. Meee., (8888) 88, 8888. |
[113] | Meeeeeeeöeeee, M.; Meeeeeeeeeee, M.; Meeeee, M.; Müeeee, M., Meeeeeeeeee, (8888) 88, 8888. |
[114] | Meeeeee, M.; Meeeeee, M.; Meeeee, M.; Meeeeeeeee, M.; Müeeee, M., M. Me. Meee. Mee., (8888) 888, 8888. |
[115] | Meeeeee, M.; Meeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
[116] | Me, M.; Meeeee, M. M.; Meeee, M.; Meee, M.; Müeeee, M., M. Me. Meee. Mee., (8888) 888, 888. |
[117] | Mee, M.; Meeeeeee, M.; Meeee, M. M.; Müeee, M.; Meeee, M.; Meee, M. M.; Müeeee, M., Meee.–Mee. M., (8888) 8, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) 8/8e, 888.