Synthesis of novel C2-symmetric and enantiomerically pure bisbenzoxazoles and bisbenzothiazoles derived from l- and d-tartaric acids
摘要:
Five pairs of novel G-symmetric and enantiomerically pure bisbenzoxazoles and a pair of bisbenzothiazoles derived from L- and D-tartaric acids have been synthesized from L- and D-2,3-O-isopropylidenetartaric dichlorides and o-aminophenol derivatives or o-amino thio phenol, respectively, in two- or one-step reactions. The mechanism for the formation of bisbenzoxazoles and bisbenzothiazoles was suggested. The UV and H-1 NMR spectra showed that no coordination between the bisbenzoheterazoles and Cu(I) or Ni(II) cations occurred due to the lack of a sufficiently basic nitrogen donor atom in the benzoheterazole moiety. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of novel C2-symmetric and enantiomerically pure bisbenzoxazoles and bisbenzothiazoles derived from l- and d-tartaric acids
摘要:
Five pairs of novel G-symmetric and enantiomerically pure bisbenzoxazoles and a pair of bisbenzothiazoles derived from L- and D-tartaric acids have been synthesized from L- and D-2,3-O-isopropylidenetartaric dichlorides and o-aminophenol derivatives or o-amino thio phenol, respectively, in two- or one-step reactions. The mechanism for the formation of bisbenzoxazoles and bisbenzothiazoles was suggested. The UV and H-1 NMR spectra showed that no coordination between the bisbenzoheterazoles and Cu(I) or Ni(II) cations occurred due to the lack of a sufficiently basic nitrogen donor atom in the benzoheterazole moiety. (C) 2002 Elsevier Science Ltd. All rights reserved.
Five pairs of novel G-symmetric and enantiomerically pure bisbenzoxazoles and a pair of bisbenzothiazoles derived from L- and D-tartaric acids have been synthesized from L- and D-2,3-O-isopropylidenetartaric dichlorides and o-aminophenol derivatives or o-amino thio phenol, respectively, in two- or one-step reactions. The mechanism for the formation of bisbenzoxazoles and bisbenzothiazoles was suggested. The UV and H-1 NMR spectra showed that no coordination between the bisbenzoheterazoles and Cu(I) or Ni(II) cations occurred due to the lack of a sufficiently basic nitrogen donor atom in the benzoheterazole moiety. (C) 2002 Elsevier Science Ltd. All rights reserved.