Using Host–Guest Complexation to Fold a Flexible Linear Organic String: Kinetically Controlled Syntheses of [3]Catenanes and a Five‐Membered Molecular Necklace

Abstract

Ringe und Ketten: Drei [3]Catenane und eine fünfteilige Perlenkette ([5]MN) mit bis zu 60‐ bzw. 92‐gliedrigen Ringen als zentralen Einheiten wurden synthetisiert. Die Synthese ging von den entsprechenden Komplexen aus, in denen die eingefädelten flexiblen linearen Gäste in ungefähr rechten Winkeln gebogen waren, um kinetisch kontrollierte Makrocyclisierungen zu erleichtern.

A Two‐Stage Molecular Retractable Cable Featuring Push‐Button and Rotary Two‐Way Switching Modes

“…Removal of the tosyl protecting group of [ 3 ][PF 6 ] under acidic conditions, followed by anion exchange, gave the threadlike salt [ 4 ‐H][2 PF 6 ] in 63 % yield. Addition of stopper unit 2 to a mixture of the molecular cage 5 (13 m M ) and threadlike salt [ 4 ‐H][2 PF 6 ] (26 m M ) in CH 3 NO 2 afforded the corresponding [2]rotaxane [ 6 ‐H][3 PF 6 ] in 40 % yield after ion exchange and chromatography (Scheme ) 12…”

Efficient self-assembly of heterometallic triangular necklace with strong antibacterial activity

“…The early research of molecular necklace could be traced back to the work reported by Sauvage et al, who generated a mixture of molecular necklaces by accident in a very low yield and characterized their structures by using electrospray ionization mass spectrometry (ESI-MS) 29 . Moreover, Stoddart et al [30][31][32] , Chiu et al 33 , Grubbs et al 34 , and Wu et al 35 also reported a series of molecular necklaces through covalent synthesis assisted by weak donor-acceptor π-π interactions or dynamic covalent chemistry, but the yield was also relatively low. Notably, Kim and coworkers realized the highly efficient assembly of molecular necklaces by taking advantage of coordination bonds and cucurbituril-based host-guest chemistry, which is definitely a big breakthrough [36][37][38] .…”