Sequential Alkylation of Tröger's Base. An Approach to New Chiral Ligands

Harmata, Michael; Rayanil, Kanok‐on; Barnes, Charles L.

doi:10.1080/10610270600853477

Cited by 20 publications

(13 citation statements)

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“…Easy-to-perform bridge replacement in Trçgers base analogues can therefore be considered as an efficient approach to the fine tuning of molecular geometry. Harmata and co-workers demonstrated deprotonation at the benzylic CH 2 of (S,S)-1 with BuLi in the presence of BF 3 · Et 2 O followed by stereoselective reaction of the carbanion with various electrophiles (see [52] and ref. cit.…”

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confidence: 97%

Recent Developments in Synthetic Chemistry, Chiral Separations, and Applications of Tröger's Base Analogues

Sergeyev

2009

Helvetica Chimica Acta

132

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Trçgers base is a well-known chiral molecule with a few unusual structural features. The chemistry of Trçgers base analogues has been greatly developed over the last 20 years, and numerous interesting applications in supramolecular chemistry and in molecular recognition have emerged. This Review gives a short overview of the chemistry of Trçgers base and its analogues, with particular focus on recent achievements in synthesis, enantiomer separations, and applications.

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mentioning

confidence: 97%

Recent Developments in Synthetic Chemistry, Chiral Separations, and Applications of Tröger's Base Analogues

Sergeyev

2009

Helvetica Chimica Acta

132

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“…The two bridgehead nitrogen atoms are H-bond acceptors and act as the main catalytically active sites, while the aromatic planes are characterized by a dihedral angle [ 187 ] of 80–114°. This rather rigid structure, resembling a chiral cavity roughly 1 nm long [ 188 , 189 ], makes these compounds potential as ligands in asymmetric applications. Moreover, various parts of their skeleton can be structurally altered, which gives the potential for refining their properties.…”

Section: Applicationsmentioning

confidence: 99%

Sugar-Based Ionic Liquids: Multifaceted Challenges and Intriguing Potential

2021

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Carbohydrates represent a promising option in transitioning from oil-based chemical resources to renewable ones, with the goal of developing chemistries for a sustainable future. Cellulose, hemicellulose, and largely available monosaccharides already provide useful chemical building blocks, so-called platform chemicals, such as levulinic acid and hydroxymethyl furfural, as well as solvents like cyrene or gamma-valerolactone. Therefore, there is great anticipation for novel applications involving materials and chemicals derived from sugars. In the field of ionic liquids (ILs), sugar-based ILs have been overlooked for a long time, mainly on account of their multistep demanding preparation. However, exploring new strategies for accessing sugar-based ILs, their study, and their exploitation, are attracting increasing interest. This is due to the growing concerns about the negative (eco)toxicity profile of most ILs in conjunction with their non-sustainable nature. In the present review, a literature survey concerning the development of sugar-based ILs since 2011 is presented. Their preparation strategies and thermal behavior analyses, sorted by sugar type, make up the first two sections with the intention to provide the reader with a useful guide. A final overview of the potential applications of sugar-based ILs and their future perspectives complement the present analysis.

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“…Harmata's methodology from 1996 involved the metalation of the benzylic methylene groups by treatment of TB ( 1 ) with BF 3 · OEt 2 followed by n BuLi and then quenching with an electrophile to give the exo ‐monosubstituted species. exo , exo ‐Disubstitution could also be achieved by sequential monometalation and electrophilic quenching (Scheme ) 63…”

Section: Functionalization Of Tröger's Basementioning

confidence: 99%

“…The downside of Harmata's procedure is that disubstituted analogues have to be synthesized in a sequential manner, resulting in decreased overall yields 63. It was demonstrated that exo ‐6‐substituted TB analogues (R = –CH 2 OH, –CPh 2 OH, –CH 2 CPh 2 OH, or –CH 2 OCH 2 CPh 2 OH) were reasonably good asymmetric inductors in additions of Et 2 Zn to aromatic aldehydes 61b…”

Section: Functionalization Of Tröger's Basementioning

confidence: 99%