Single functionalization of fenestrindane and centrohexaindane at the molecular periphery

Abstract

The single functionalization of the parent centropolyindane hydrocarbons fenestrindane (2) and centrohexaindane (3) at the molecular arene periphery has been studied. The monoformylation of 2 and 3 using the Rieche method resulted in the corresponding aldehydes, 7 and 10, in 23% and 35% yield, respectively. The Friedel-Crafts acetylation of 2 furnished 2-acetylfenestrindane (8) in 53% yield, and the Baeyer-Villiger oxidation of 7 followed by hydrolysis resulted in the 2-hydroxyfenestrindane (9) in 72% yield. The results show that electrophilic attack at one of the eight or, respectively, even 12 equivalent positions of 2 and 3 is a viable method for the monofunctionalization of these polycyclic aromatic hydrocarbons.

A Perspective on Centrohexaindane Chemistry and a Deep‐Sleeping “Cartesian” Seed

“…Only one single monofunctionalized centrohexaindane has been reported, viz., carbaldehyde 6 b (X = CHO, Y = H, Figure 6), obtained by post-functionalization of hydrocarbon 5 in moderate yield (35 %). [30] Like the yet unknown disubstituted congeners 6 a, these structures are achiral. Homocondensation of suitably X,Y-difunctionalized derivatives, such as the yet unknown 2-amino-3-bromo derivative 11 by Buchwald-Hartwig reaction, would yield the bis-centrohexaindane 12 as a first step towards larger orthogonally extended constructs and networks based on hydrocarbon 5 (Scheme 1).…”

“…Only one single monofunctionalized centrohexaindane has been reported, viz ., carbaldehyde 6 b (X=CHO, Y=H, Figure 6), obtained by post‐functionalization of hydrocarbon 5 in moderate yield (35 %) [30] . Like the yet unknown disubstituted congeners 6 a , these structures are achiral.…”

Dodecabromo‐ and Dodecaiodocentrohexaindane: Td‐Symmetrical Key Building Blocks for Twelve‐Fold Cross‐Coupling Reactions and Six‐Fold Orthogonal Extension

“…So far, the only derivative of 1 bearing functional groups at all of the twelve peripheral positions is 2,3,6,7,10,11,14,15,20,21,26,27‐dodecamethoxycentrohexaindane ( 2 ), synthesized in low overall yield from veratrole‐based building blocks . Beside single functionalization of 1 , six‐fold peripheral nitration was achieved recently, promising an access to various highly N ‐functionalized congeners including the particularly interesting, but yet unknown dodecaamino derivative . In the same vein, twelve‐fold bromination and iodination of 1 represent most desirable key steps for “Cartesian” extension of the centrohexaindane core.…”