Bis- and mono(m-benzoic acid)-functionalized pillar[5]arenes

Abstract

Installation of m-benzoic acid functionalities on pillar[5]arene rims resulted in bis- and mono(m-benzoic acid)-functionalized pillar[5]arenes 1 and 2. Bis(m-benzoic acid)-functionalized pillar[5]arene 1 was able to self-assemble to form one-dimensional channels with DMF molecules residing in pillar[5]arene cavities. Esterification of two carboxylic acids in 1 with decane-1,10-diol did not afford a [1]catenane, but a bicyclic compound. Although 1-decanol esterification of mono(m-benzoic acid)-functionalized pillar[5]arene 2 did not form a self-included [1]pseudorotaxane-like structure, a mono(decyl m-benzoate)-functionalized pillar[5]arene bearing an ethyl acetate chain was found to form a self-included complex with the ethyl acetate moiety residing inside the pillar[5]arene cavity.

Noncovalently bound and mechanically interlocked systems using pillar[n]arenes

“…As another example, A1,A2-bis-( m -benzoic acid)-appended pillar[5]arene formed a bicyclic structure by linking its side chains with 1,10-decanediol ( P51 ). 147 The alkyl chain was located outside the pillar[5]arene ring, probably owing to the rigid m -benzoate segment, allowing host–guest chemistry with 22 in the pillar[5]arene cavity.…”

Hydroxy-Rich Pillar[5]arene-Based Nanoporous Aromatic Frameworks (PAFs) for Efficient CO2 Uptake under Ambient Conditions

“…As shown in Scheme , 2TfO-4Ph-EP5 , prepared by following a procedure described in the previous report, was reacted with tetrakis­(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)­phenyl)­methane (TBPM) under typical Suzuki reaction conditions to result in PAF-EP5 whose ethyl groups were removed through a reaction with BBr 3 in DCM to afford the hydroxy-rich porous aromatic framework PAF-P5-OH .…”

Pillarquinones and Pillararenequinones

“…Table 1 summarizes the partial oxidation processes of the pillar[5]arenes 1 a-1 d to the presently known pillar [5-m]arene[m]quinones 4-6, 8 and 9 (Figure 2). [5,[13][14][15][16][17][18][19][20][21][22][23] Certain molar ratios 1/oxidizing agent led to the formation of a preferred number m of quinone rings in the product. A column chromatography was conventionally used for the separation and purification of the products.…”

“…[30,31] The subsequent oxidation to pillararenequinones is preparatively less advisable and is limited to special cases such as 13 a. [26] The reverse process, the reduction of pillararenequinones to pillararenehydroquinones was practiced many times by applying NaBH 4 [14,17,20,21,23,32] , Na 2 S 2 O 4 [13,15,18,24,25,28] or Zn/AcOH [26] as reducing agents. The yields were very high, in many cases quantitative.…”