Novel strategy for the synthesis of chiral pseudo-ortho-substituted hydroxy[2.2]paracyclophane-based ligands from the resolved 4-bromo-12-hydroxy[2.2]paracyclophane as a parent compound

The crystal structure of tert-butyl 2-(4-(12-bromo [2.2]paracyclophanyl)carbamoyl)pyrrolidine-1-carboxylate, C26H31BrN2O3

C26H31BrN2O3, orthorhombic, P212121 (no. 19), a = 11.01(1) Å, b = 13.227(12) Å, c = 16.458(14) Å, V = 2397(4) Å3, Z = 4, R gt(F) = 0.0367, wR ref(F 2) = 0.0775, T = 298(2) K.

Synthesis of Twisted Anthracenes: Induction of Twist Chirality by the Planar Chiral [2.2]Paracyclophane

Planar chiral [2.2]paracyclophane was employed as chiral scaffolds to twist an anthracene ring by tethering at its 1- and 8positions; thus, twist chirality was induced in the anthracene moiety. The chiroptical properties of the resulting molecule, including circular dichroism (CD) and circularly polarized luminescence (CPL), were found to be derived from the twist chirality. An analogous molecule bearing long alkyl chains was a viscous liquid, and its liquid film exhibited good CD and CPL profiles. The theoretical studies are carried out to determine the origin of these properties in the ground and excited states, which reproduced well the experimental results.

Enantiopure planar chiral [2.2]paracyclophanes: Synthesis and applications in asymmetric organocatalysis

This short review focuses on enantiopure planar chiral [2.2]paracyclophanes (pCps), a fascinating class of molecules that possess an unusual three-dimensional core and intriguing physicochemical properties. In the first part of the review, different synthetic strategies for preparing optically active pCps are described. Although classical resolution methods based on the synthesis and separation of diastereoisomeric products still dominate the field, recent advances involving the kinetic resolution of racemic compounds and the desymmetrization of meso derivatives open up new possibilities to access enantiopure key intermediates on synthetically useful scales. Due to their advantageous properties including high configurational and chemical stability, [2.2]paracyclophanes are increasingly employed in various research fields, ranging from stereoselective synthesis to material sciences. The applications of [2.2]paracyclophanes in asymmetric organocatalysis are described in the second part of the review. While historically enantiopure pCps have been mainly employed by organic chemists as chiral ligands in transition-metal catalysis, these compounds can also be used as efficient catalysts in metal-free reactions and may inspire the development of new transformations in the near future.

Regioselective Functionalization of [2.2]Paracyclophanes: Recent Synthetic Progress and Perspectives

[2.2]Paracyclophane (PCP) is a prevalent scaffold that is widely utilized in asymmetric synthesis, π-stacked polymers, energy materials, and functional parylene coatings that finds broad applications in bio- and materials science. In the last few years, [2.2]paracyclophane chemistry has progressed tremendously, enabling the fine-tuning of its structural and functional properties. This Minireview highlights the most important recent synthetic developments in the selective functionalization of PCP that govern distinct features of planar chirality as well as chiroptical and optoelectronic properties. Special focus is given to the function-inspired design of [2.2]paracyclophane-based π-stacked conjugated materials by transition-metal-catalyzed cross-coupling reactions. Current synthetic challenges, limitations, as well as future research directions and new avenues for advancing cyclophane chemistry are also summarized.

Synthesis and characterization of rigid [2.2]paracyclophane–porphyrin conjugates as scaffolds for fixed-distance bimetallic complexes

This work presents a new approach to prepare mono- and disubstituted linear rigid bimetallic [2.2]paracyclophane–porphyrin conjugates via palladium-mediated Stille cross-coupling reaction. The metalated porphyrin moiety can be varied allowing convenient access to modular metal–metal fixed-distance Cu/Zn complexes.

Design and synthesis of mono- and disubstituted linear rigid metalated [2.2]paracyclophane–porphyrin conjugates is presented.

Chiral linker-bridged bis-N-heterocyclic carbenes: design, synthesis, palladium complexes, and catalytic properties

A series of chiral linker-bridged bis(NHC) palladium complexes have been designed, synthesized and showed obviously different catalytic properties in the asymmetric Suzuki–Miyaura coupling reactions.

[2.2]Paracyclophane-derived monodentate phosphoramidite ligands for copper-catalyzed asymmetric conjugate addition of diethylzinc to substituted chalcones

Copper-catalyzed asymmetric conjugate addition of diethylzinc to chalcones could be realized by using [2.2]paracyclophane-derived monodentate phosphoramidite ligands. The excellent yield and enantioselectivity (up to 98% yield and 95% enantiomeric excess) could be realized with low catalyst loading of 1.0 mol % and low ligand loading of 1.2%.