Synthesis of enantiomerically pure Tröger's base derivatives via chiral disulfoxides

Abstract

A practical and scalable method for synthesis and resolution of 4,10-di-substituted Tröger's base derivatives is described. By combination of circular dichroism (CD) spectra and X-ray diffraction (XRD) analysis method, the absolute configuration on two sterogenic nitrogen atoms of the crucial intermediate (-)-diastereomer is assigned as 5S,11S.

Formation of Ternary Inclusion Crystal and Enantioseparation of Alkyl Aryl Sulfoxides by the Salt of Urea-Modified l-Phenylalanine and an Achiral Amine

“…Enantioseparation of such guest compounds is more challenging since there are fewer hydrogen-bonding interactions with the host molecules. Of these hydrogen-bond-accepting guest molecules, chiral sulfoxides are the desired target compounds since they are important chiral auxiliaries, − pharmaceutical compounds, etc. Enantioseparation of alkyl aryl sulfoxides has been reported via inclusion crystallization with BINOL, bile acids, or dipeptides. − We have also reported their enantioseparation with supramolecular hosts; however, the enantiopure primary amine component of the host is not a naturally occurring compound and is expensive to purchase …”

Synthetic strategies and diversification of dibenzo[1,5]diazocines

“…[24][25][26][27] By contrast, the presence of methylene-, nitrogen-or oxo-bridges across the ring imparts the structure with a rigid V-shaped conformation. 28,29 Interestingly, the boat structure of dibenzo [1,5]diazocine is reversible and can be converted to a Hückel dianion with an aromatic planar conformation and with ten π-electrons via a twoelectron reduction process (Scheme 1a). [30][31][32][33] Furthermore, the reductive-ring closure reaction of dichlorodibenzo[b,f] [1,5]diazocine leads to the formation of a diverse range of π-conjugated indolo [2,3-b]indole derivatives (Scheme 1b).…”