41784-92-3

Upstream product

• 38309-89-6 2,7-bis(bromomethyl)naphthalene 
• 603-35-0 triphenylphosphine 
• 582-16-1 2,7-dimethylnaphthalene 
• 582-17-2 2,7-Dihydroxynaphthalene 
• 151391-00-3 methanesulfonic acid 1,1,1-trifluoro-1,1'-(2,7-naphthalenedidyl) ester 

Downstream Products

• 133966-27-5 2,7-Bis-[(E)-2-(2-bromo-5-methoxy-phenyl)-vinyl]-naphthalene 
• 88111-69-7 2,7-bis[2-(4-bromophenyl)ethinyl]naphthalene 
• 1383986-70-6 2,7-bis[2-(4-((trimethylsilyl)ethynyl)phenyl)ethenyl]naphthalene 

Relevant academic research and scientific papers

Chiral Self-Discrimination and Guest Recognition in Helicene-Based Coordination Cages

Chiral nanosized confinements play a major role for enantioselective recognition and reaction control in biological systems. Supramolecular self-assembly gives access to artificial mimics with tunable sizes and properties. Herein, a new family of [Pd2L4] coordination cages based on a chiral [6]helicene backbone is introduced. A racemic mixture of the bis-monodentate pyridyl ligand L1 selectively assembles with PdII cations under chiral self-discrimination to an achiral meso cage, cis-[Pd2L1P2L1M2]. Enantiopure L1 forms homochiral cages [Pd2L1P/M4]. A longer derivative L2 forms chiral cages [Pd2L2P/M4] with larger cavities, which bind optical isomers of chiral guests with different affinities. Owing to its distinct chiroptical properties, this cage can distinguish non-chiral guests of different lengths, as they were found to squeeze or elongate the cavity under modulation of the helical pitch of the helicenes. The CD spectroscopic results were supported by ion mobility mass spectrometry.

Helical Threads: Enantiomerically Pure Carbo[6]Helicene Oligomers

We report the synthesis of enantiomerically pure carbo[6]helicene oligomers with buta-1,3-diyne-1,4-diyl bridges between the helicene nuclei. The synthesis of monomeric (±)-2,15-bis[(triisopropylsilyl)ethynyl]carbo[6]helicene was achieved in 25 % yield over six steps. Pure (+)-(P)- and (?)-(M)-enantiomers were obtained by HPLC on a chiral stationary phase. The dimeric (+)-(P)2- and (?)-(M)2-configured and the tetrameric (+)-(P)4- and (?)-(M)4-configured oligomers were obtained by sequential oxidative acetylenic coupling. The ECD spectra of the tetrameric oligomers displayed large Cotton effect intensities of Δ?=?851 m?1 cm?1 at λ=370 nm ((M)4-enantiomer). We transformed the buta-1,3-diyne-1,4-diyl bridge in the dimeric (P)2 and (M)2 oligomer by heteroaromatization into a thiene-2,5-diyl linker. Although the resulting chromophore showed reduced ECD intensities, it exhibited a remarkably strong fluorescence emission at 450–500 nm, with an absolute quantum yield of 25 %.

One-step synthesis of [16]helicene

Abstract A single-strand arylene-vinylene precursor containing four phenylene and three naphthylene units linked together with six vinylene spacers undergoes helical folding via sextuple photocyclization to give a [16]helicene core in a single step. The phenylene and naphthylene units are arranged in the precursor such that unfavorable side reactions (anthracene or benzoperylene formation) are avoided, and this is the key to the success of the one-step synthesis of [16]helicene, which is the longest [n]helicene that has been synthesized to date. An aromatic spiral layer: A [16]helicene core was prepared in a single step by sextuple photocyclization from a single-strand arylene-vinylene precursor containing four phenylene and three naphthylene units linked by six vinylene spacers. X-ray crystallographic analysis revealed the triple-layered structure. A new guideline for the design of precursor olefins resulted in the longest helicene synthesized to date.

The first helical-chiral phosphane ligands: rac-[5]- and rac-[6]-heliphos

The syntheses of two helical, chiral phosphanes in their racemic forms are described. Their helicene backbone was built up using an improved photocyclization approach. The phosphorus functionalities were introduced in the last step. Up to now, separation of the enantiomers of the helicene phosphanes could be achieved analytically but not on a preparative scale.

First enantioselective catalysis using a helical diphosphane

The synthesis of 2,15-bis(diphenylphosphino)-hexahelicene (PHelix) in enantiomerically pure form and its use as a helical ligand for enantioselective rhodiumcatalyzed hydrogenation are described.