Carbon nanohoops and methods of making
View Patent ↗The present invention provides cycloparaphenylene compounds, their macrocyclic precursors, and methods for making the compounds. The cycloparaphenylene compounds can be used to prepare armchair carbon nanotubes.
1. A method of preparing a compound of formula I:
wherein
each R is hydrogen, and
subscript n is an integer selected from the group consisting of 6, 9, 12, 15, 18, 21, 24, 27 and 30,
the method comprising:
contacting a reducing agent and a compound of formula II:
wherein
each R 1 is independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 1-6 heteroalkyl, C 3-8 cycloalkyl, heterocycloalkyl, aryl and heteroaryl, and
subscript m is an integer from 2 to 10,
thereby affording the compound of formula I.
2. The method of claim 1 , wherein the reducing agent comprises a one-electron reductant.
3. The method of claim 1 , wherein the reducing agent comprises an alkali metal and an aryl group.
4. The method of claim 1 , wherein the reducing agent comprises a naphthalenide.
5. The method of claim 1 , wherein the method further comprises:
contacting a benzoquinone and 1,4-diiodobenzene to prepare a compound of formula III:
wherein
each R 1 is C 1-6 alkyl,
each R 2 is independently selected from the group consisting of iodo and a boronate; and
contacting a plurality of compounds of formula III, wherein each R 2 is iodo for at least one compound of formula III and each R 2 is a boronate for at least one compound of formula III, to prepare a compound of formula II.
6. The method of claim 1 , wherein subscript n is selected from the group consisting of 9, 12, 15, 18, 21, 24, 27, and 30, and wherein subscript m is an integer from 3 to 10.