Regioselective Synthesis of 4,7,12,15-Tetrasubstituted [2.2]Paracyclophanes: A Modular Route Involving Optical Resolution

Biliz F., ÇAKICI M.

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, cilt.2021, sa.34, ss.4828-4834, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 2021 Sayı: 34
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1002/ejoc.202100762
  • Dergi Adı: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Applied Science & Technology Source, CAB Abstracts, Chemical Abstracts Core, Chimica
  • Sayfa Sayıları: ss.4828-4834
  • Anahtar Kelimeler: Benzal chlorides, Chiral resolution, Cyclophanes, Planar chirality, Rieche formylation, ABSOLUTE-CONFIGURATION, SUBSTITUTION PATTERNS, CHIRAL RESOLUTION, BUILDING-BLOCKS, PLANAR, EFFICIENT, FORMYLATION, DERIVATIVES, POLYMERS
  • Atatürk Üniversitesi Adresli: Evet

Özet

A practical synthetic method for preparing bis-(para)-pseudo-ortho and bis-(para)-pseudo-meta type 4,7,12,15-tetrasubstituted [2.2]paracyclophanes is reported. Regioselective double Rieche formylation was successfully applied to the corresponding dibromo[2.2]paracyclophanes under slightly modified conditions. Aldehydes reacted in an unknown direction with Rieche formylation agents, dichloromethyl methyl ether and titanium(IV) tetrachloride, leading to the formation of benzal chlorides. Formylated products were obtained after hydrolysis of these benzal chloride derivatives. Optical resolution was performed with the diastereomer method and (R-P)-4,12-dibromo-7,15-diformyl[2.2]paracyclophane was successfully obtained in an enantiomerically pure form (99 % ee). Their synthetic utility is demonstrated with some exploratory transformations to access corresponding differently functionalized tetrasubstituted [2.2]paracyclophane derivatives.