Zur chemie des cyclooctatetraenyldilithiums: 9.(N,N-dialkylamino)-9-phosphabicyclo[4.2.1]nona-2,4,7-triene, 9-halogen-9-phosphabicyclo[14.2.1]Nona-2,4,7-triene und deren nucleophile substitution, 9-H-9-phosphabicyclo]4.2.1]nona-2,4,7-trien
Review articleOpen access
G. Märkl - No affiliation found
1984/09/18 Full-length article DOI: 10.1016/0022-328X(84)80503-3
Journal: Journal of Organometallic Chemistry
AbstractN, N(Dialkylamino)-dichlorophosphanes react with cyclooctatetraenyldilithium to give the syn/anti-9-(N,N-dialkylamino)-9-phosphabicyclo[4.2.1]nona-2,4,7-trienes 5 (syn/anti ratio 100/0 to 54/46); syn-9-(N,N-Diethylamino)-9- phosphabicyclo[4.2.1]nona-2,4,7-triene (5a) is halogenated with PCl3 and PBr3 respectively to form the syn/anti-9-chloro(9-bromo)-9-phosphabicyclo[4.2.1.]nona-2,4,7- trienes 6a,6b (ratio of the isomers 30/70). The 9-fluoro derivative 6c can be obtained from 6a by Cl → F exchange with KF/-crown-6 as a syn/anti mixture (60/40). The 1H and 31P NMR spectra of all the syn/anti isomers are discussed.The stereochemistry of the nucleophilic substitution of syn/anti-9-chloro-phosphane 6a with lithium alkyls, with phenolates, thiophenolates and alcoholates is studied.By reduction of 6a with LiAlH4 the 9-H-9-phosphabicyclo[4.2.1]nona-2,4,7-triene 12 is obtained as a mixture of the syn/anti isomers (38/62).The phosphide anion 13, obtained by reaction of 12 with n-BuLi, does not rearrange into the 10π-system of the trans,cis,cis,cis-phosphoninyl anion 2.
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