Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• M. Angeles Gutierrez Lopez Mei-Ling Tan Giacomo Renno Augustina Jozeliunaite J. Jonathan Nue-Martinez Javier Lopez-Andarias Naomi Sakai Stefan Matile Department of Organic Chemistry, University of Geneva, Geneva, Switzerland 10.3762/bjoc.19.140 Abstract Anion–π catalysis, introduced in 2013

• , stands for the stabilization of anionic transition states on π-acidic aromatic surfaces. Anion–π catalysis on carbon allotropes is particularly attractive because high polarizability promises access to really strong anion–π interactions. With these expectations, anion–π catalysis on fullerenes has been

• introduced in 2017, followed by carbon nanotubes in 2019. Consistent with expectations from theory, anion–π catalysis on carbon allotropes generally increases with polarizability. Realized examples reach from enolate addition chemistry to asymmetric Diels–Alder reactions and autocatalytic ether cyclizations

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• noncovalent forces, hydrogen bonding interactions play a central role in noncovalent catalysis [2] while halogen bonding interactions have lately been exploited as a new tool to catalyze a diverse array of reactions [3][4][5]. In addition, nonclassical interactions such as anion–π [6][7][8][9][10][11] as well

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• with N-aryloxyamides, driven by noncovalent anion–π interactions, which has been described for the first time in a light-promoted process. The construction of C–P bonds Many compounds contain phosphorus, which has gained a high degree of interest in materials, agriculture, medical science, and biology

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

• Sachin S. Burade,
• Sushil V. Pawar,
• Tanmoy Saha,
• Navanath Kumbhar,
• Amol S. Kotmale,
• Manzoor Ahmad,
• Pinaki Talukdar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

• various diseases such as cystic fibrosis, Dent disease, Bartter syndrome, and epilepsy [34][35][36][37]. In order to mimic the regulatory functions in living systems, a wide range of anion transporters have been investigated that include peptides [38][39][40][41][42][43], oligoureas [44][45], anion-π

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• -triazole units to more electrophilic 1,2,3-triazolium units by influencing both hydrogen bonding-like and anion–π interactions. Moreover, halogen bond (XB) and chalcogen bond (ChB) interactions (see Figure 1) also been applied for the selective detection of anions by exchanging C5–H protons with halogens

• in the literature in which they bind to the anionic species by utilizing multiple noncovalent interactions based on electrostatics, including hydrogen bonding (HB), anion–π interactions [30], and on Lewis acidity/basicity [31]. 2.1. Bile acid-based 1,2,3-triazolium macrocycles Bile acid-based

• between anions and the NDI motif [59]. NDI was chosen due to its excellent photochemical and electrochemical properties. In addition, the electron deficiency and aromatic nature of NDI is important for anion–π interactions [60] to control the charge-transfer properties. It also has been observed that in

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• adopt the conformation in which three phthalimide units are cis,trans-orientated. Acting as electron-deficient macrocyclic hosts, the synthesized O6-corona[3]arene[3]tetrazines self-regulated conformational structures to complex anions in the gas phase and in the solid state owing to the anion–π

• noncovalent interactions between anions and the tetrazine rings. Keywords: anion–π interactions; coronarenes; host–guest complexation; N-functionalized phthalimides; O6-corona[3]arene[3]tetrazines; Introduction Synthetic macrocycles [1][2] are always attractive and important because they are unique

• functionalized coronarene macrocycles. Moreover, the electronic feature of the phthalimide would render the resulting O6-corona[3]arene[3]tetrazines the electron-deficient hosts to form anion-π complexes [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. We report herein the synthesis, structure

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• chemistry reactions, as it relies on soft force [97][98] or non-covalent interactions [2] such as hydrogen bonding [99], cation–π [100][101][102], anion–π [103], hydrophobic effect [104][105], halogen bonding [106][107][108][109], etc. As enzymes are structurally complex entities and are difficult to modify

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• without significant erosion in yield or reaction time [55]. Interestingly, the ability of catalysts L13 to catalyze the reaction was attributed to 1-chloroisochroman activation through Coulombic interactions coupled with anion–π bonding. Thus, L13 was proposed to promote ionization of 1-chloroisochroman

• chloride complexation, the provided X-ray data are consistent with L13 acting as hydrogen bond donors (Scheme 10B). The published X-ray data for the chloride and bromide salts of L13 with R2 = C6F5 indeed provide evidence of anion–π bonding with the C6F5 group. In addition, we also noted that there is

Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

• Antonio Avellaneda,
• Courtney A. Hollis,
• Xin He and
• Christopher J. Sumby

Beilstein J. Org. Chem. 2012, 8, 71–80, doi:10.3762/bjoc.8.7

• bladed propeller conformation in solution. Compound 3 is considerably more electron deficient than previously reported hexaaryl[3]radialenes, with reduction potentials of −0.06 and −0.45 V in CH2Cl2. The compounds mostly display red fluorescence with large Stokes shifts. Keywords: anion–π interactions

• tetradentate bridge [18][19]. Hexa(4-pyridyl)[3]radialene also acts as a bridging ligand in a 3-D coordination polymer with AgClO4 [20], while isomorphous 6,3-connected 2-D coordination polymers were obtained when hexakis(4-cyanophenyl)[3]radialene was reacted with AgPF6 and AgClO4 [21]. Anion–π interactions

• have recently received much attention [22][23][24][25][26], where the π-system is typically an electron deficient heterocyclic system. The electron deficient nature of the hexaaryl[3]radialenes is borne out in structures of these compounds which also show anion–π interactions and CH···Xanion hydrogen

Anion–π interactions influence pK_a values

• Christopher J. Cadman and
• Anna K. Croft

Beilstein J. Org. Chem. 2011, 7, 320–328, doi:10.3762/bjoc.7.42

• analysis. Contributions to the relative pKa' values have been interpreted, using M06-2X DFT calculations, as consisting of two components: A small contribution from initial OH–π bonding in the starting materials and a larger contribution from anion–π interactions in the products. Such effects have

• implications for a range of other systems. Keywords: anion–π; DFT; intramolecular interaction; LFER; pKa; Introduction There are numerous examples in nature of interactions involving aromatic systems and these interactions underpin many modern supramolecular binding agents, with clear applications in

• fashion, CH–π interactions and anion–π interactions have been identified as influencing binding in a number of systems. Since key computational investigations have indicated that anion–π interactions might be very important [2][3][4], which is also supported by strong circumstantial evidence from crystal