Transition metal catalysed synthesis of tetrahydro derivatives of [5]-, [6]- and [7]helicene

Authors
Stara, IG Stary, I Kollarovic, A Teply, F Vyskocil, S Saman, D
Citation
Ig. Stara et al., Transition metal catalysed synthesis of tetrahydro derivatives of [5]-, [6]- and [7]helicene, TETRAHEDR L, 40(10), 1999, pp. 1993-1996
Citations number
19
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
10
Year of publication
1999
Pages
1993 - 1996
Database
ISI
SICI code
0040-4039(19990305)40:10<1993:TMCSOT>2.0.ZU;2-S
Abstract
Tetrahydro analogues of [5]-, [6]- and [7]helicene have been easily prepare d by intramolecular [2+2+2] cycloisomerization of appropriate triynes under CpCo(CO)(2)/PPh3 or Ni(cod)(2)/PPh3 catalysis. This nonphotochemical metho dology allows enantioselective synthesis of a helical skeleton employing th e Ni(cod)(2)/(S)-(-)-MOP catalytic system. On reaction with DDQ, tetrahydro [5]helicene was transformed to [5]helicene. (C) 1999 Elsevier Science Ltd. All rights reserved.