1380313-98-3Relevant academic research and scientific papers
Synthesis of polycyclic aromatic hydrocarbon-based nanovehicles equipped with triptycene wheels
Jacquot De Rouville, Henri-Pierre,Garbage, Romain,Cook, Rita E.,Pujol, Adeline R.,Sirven, Agnes M.,Rapenne, Gwenael
, p. 3023 - 3031 (2012/04/23)
Two new nanovehicles that have extended aromatic platforms as the cargo zones have been obtained. Two strategies were considered for the formation of the perylene core from two naphthalene precursors. The first was based on a Scholl-type reaction involving an oxidant, and the second used a brominated derivative to perform a homocoupling reaction. The first strategy failed under diverse coupling conditions in the presence of several strong oxidants. Nevertheless, the use of CoF3 in trifluoroacetic acid triggered a dimerization reaction between two ester groups of one molecule and the naphthalene unit of another, thereby surprisingly yielding a ten-membered carbon macrocycle. The second strategy encountered a lack of reactivity of the substrate under several homocoupling conditions. The dimerization was not easily performed but Ullmann-type conditions ultimately gave the expected product. The low yield and low solubility of the product encouraged us to modify our initial design. The synthesis of a new chassis that incorporated additional tert-butyl groups improved the solubility of the molecules and also prevented overcyclization of the aromatic platform by blocking these positions. Some p-phenylene spacers were also intercalated between the iodine and perylene centers to increase the reactivity of the halide towards coupling reactions. Two new chassis were obtained by Scholl-type oxidative coupling using FeCl 3 as the oxidant. The introduction of four triptycene wheels allowed the formation of the two corresponding nanovehicles. Deux nouveaux nanovehicules ont ete obtenus avec une plateforme polyaromatique pouvant servir de zone de chargement. Deux strategies de synthese ont ete considerees pour la formation du noyau perylene a partir de deux precurseurs naphtaleniques. La premiere a fait intervenir une reaction de type Scholl mettant en jeu un oxydant, tandis que la seconde a mis en uvre un derive brome afin de realiser un homocouplage. La premiere strategie a echoue malgre de nombreuses conditions de couplage testees. Neanmoins, les conditions utilisant CoF3 dans l'acide trifluoroacetique ont abouti a une dimerisation entre deux fonctions esters d'une molecule et le noyau naphtalene d'une seconde, conduisant a la formation d'un macrocycle a 10 chaenons. La seconde strategie a egalement souffert d'un manque de reactivite du substrat lors de l'homocouplage. La dimerisation n'a pu s'effectuer facilement, mais les conditions de type Ullmann ont finalement permis d'aboutir au compose souhaite. Le faible rendement combine a la faible solubilite du produit de cette reaction nous ont conduits a corriger le design initial. La synthese d'un nouveau chassis a ete entreprise en incorporant des groupements tert-butyles supplementaires, afin d'ameliorer la solubilite des molecules mais aussi pour eviter de surcycliser le chassis polyaromatique en bloquant ces positions. Des espaceurs p-phenylene ont egalement ete intercales entre l'atome d'iode et le noyau perylene pour ameliorer la reactivite de l'halogenure vis-a-vis des reactions de couplage. Deux nouveaux chassis ont ainsi ete obtenus par couplage oxydant de type Scholl en utilisant FeCl3 comme oxydant. L'introduction de quatre roues triptycenes a permis d'obtenir les deux nanovehicules correspondants. En route! Two new molecular nanovehicles with a large dedicated cargo zone have been synthesized according to a modular strategy based on sequential double Knoevenagel and Diels-Alder reactions. Copyright
