573-17-1Relevant articles and documents
A simple Hückel model-driven strategy to overcome electronic barriers to retro-Brook silylation relevant to aryne and bisaryne precursor synthesis
Neal, Edward A.,Werling,Jones, Christopher R.
supporting information, p. 1663 - 1666 (2021/02/26)
ortho-Silylaryl triflate precursors (oSATs) have been responsible for many recent advances in aryne chemistry and are most commonly accessed from the corresponding 2-bromophenol. A retro-BrookO- toC-silyl transfer is a key step in this synthesis but not all aromatic species are amenable to the transformation, with no functionalized bisbenzyneoSATs reported. Simple Hückel models are presented which show that the calculated aromaticity at the brominated position is an accurate predictor of successful retro-Brook reaction, validated synthetically by a new success and a predicted failure. From this, the synthesis of a novel difunctionalized bisaryne precursor has been tested, requiring different approaches to install the twoC-silyl groups. The first successful use of a disubstitutedo-silylaryl sulfonate bisbenzyne precursor in Diels-Alder reactions is then shown.
Chiral Ligand-Mediated Nucleophilic Aromatic Substitution of Naphthoic Acids: A Fast and Efficient Access to Axially Chiral Biaryls
Nguyen, Thi Thanh Thuy,Guyon, Hélène,Nguyen, Kim Phi Phung,Boussonnière, Anne,Mortier, Jacques,Castanet, Anne-Sophie
supporting information, p. 3829 - 3833 (2020/05/25)
A transition metal-free synthesis of enantioenriched biaryls from aryllithium species has been developed. This approach relies on atropoenantioselective nucleophilic aromatic substitution (SNAr) reaction of unprotected naphthoic acids. The ability of a diverse set of chiral ligands to mediate this transformation has been investigated. 1,2-diether ligands outperform their diamine counterparts and the best enantiocontrol was obtained with readily accessible enantiopure trans-1,2-dimethoxycyclohexane. This SNAr reaction offers an efficient and rapid access to enantioenriched binaphthalenes, phenylnaphthalene, and phenanthrylnaphthalenes (up to 94:6 er).
Preparation method of 9-bromophenanthrene
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Paragraph 0018; 0019; 0021-0024; 0025-0028, (2017/09/19)
The invention discloses a preparation method of 9-bromophenanthrene shown as in formula (II) that is shown in the description. The preparation method is characterized by including the steps of using phenanthrene shown in formula (I) that is shown in the description as a raw material, adding KBr bromination reagent, adding bromination reagent ZnAl-BrO3-LDHs into acetic acid and water mixed solvent, reacting at 20-70 DEG C for 2-5 hours to obtain reacted liquid that is post-treated to obtain the 9-bromophenanthrene shown as in the formula (II); the mas ratio of the phenanthrene shown as in the formula (I) to the KBr and ZnAlBrO3-LDHs is 1:0.9:0.6; the preparation method has the advantages that the preparation process is convenient, the reaction conditions are mild, low environmental pollution is caused, the requirements for equipment are low, bromine utilization rate is high, and the reaction time is short.