A New Entry to Bis‐Tröger’s Bases

Abstract

This paper reports the use of p‐phenylenediamine to prepare bis‐Tröger’s bases. The methyl,nitro‐substituted bis‐Tröger’s base 5, already previously prepared by another procedure, was obtained in fewer steps, although with no improvement in the yield of the desired syn isomer. The symmetric dinitro‐substituted bis‐Tröger’s base 17, which cannot be prepared by the older method, was then synthesized. Its structure was determined by mass spectrometry, 2D NMR spectroscopy, and, in the case of the syn isomer, by X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Use of Tröger's Base as a Scaffold for New Chiral Molecular Tweezers: Synthesis of Trimeric, Fused Tröger's Bases

“…This result is similar to those obtained in isomerization experiments of the dimeric bases 2 [5] and 4 [7].…”

“…Trögers bases show a perpendicular arrangement of the two aromatic rings [3c], as in Kagans ether, which was used by Harmata and co-workers for the synthesis of molecular tweezers [4]. In this context, we have utilized the Trögers base skeleton as a scaffold for the construction of the molecular clips 2 [5], 3 [6], and 4 [7].In this paper, we report the synthesis of chiral molecular tweezers with a trimeric, fused Trögers base skeleton. During the course of the present work, Klärner et al [8] have described the synthesis of another family of molecular tweezers of type 5, with three methylene bridges, achiral carbocylic analogues of the compounds described in this paper.…”

“…Trögers bases show a perpendicular arrangement of the two aromatic rings [3c], as in Kagans ether, which was used by Harmata and co-workers for the synthesis of molecular tweezers [4]. In this context, we have utilized the Trögers base skeleton as a scaffold for the construction of the molecular clips 2 [5], 3 [6], and 4 [7].…”

Synthesis of Versatile Nonsymmetric Amine‐ and Boron‐Functionalized Tröger's Base Derivatives, Including a Tröger's Base Amino Acid

“…The reduction procedure was adapted from a published procedure. [22] Product R f = 0.1 (25 % EtOAc/hexanes), SM R f = 0. Compound 6: Compound 5 (3.14 g, 8.5 mmol) and paraformaldehyde (1.02 g, 34.0 mmol) were dissolved in TFA (170 mL) and stirred at room temperature for 120 h. The reaction was poured into ice (300 mL) and a yellow precipitate was formed.…”

A shorter synthesis of symmetrical 2,11-dimethyl-bis-Tröger`s bases. A new molecular tweezer

“…Following a similar route starting from p-phenylenediamine, we recently succeeded in the synthesis of the symmetrical dinitro-bis-Bases 3 in only three steps (Scheme 2). [10] By treating pphenylenediamine with two equivalents of 6-nitroisatoic anhydride we obtained the bis-amide 4 that was reduced with borane-SMe 2 complex in anhydrous THF to afford the tetramine 5. Treatment of 5 with aqueous formaldehyde and conc.…”