ISSN:
0009-2940
Schlagwort(e):
Iminoboranes
;
Tantalum complexes, cyclic carbene-
;
Azaboratantalacyclobutanes
;
Azaboratantalacyclobutenes
;
Diazoniadiboratatantalacyclohexadienes
;
Chemistry
;
Inorganic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Further Reactions of Iminoboranes RB≡NR' with Neopentylidenetantalum ComplexesThe azaboratantalacyclobutanes [-NR≡-BR-CH(tBu)-Ta-CpCl2-] (3b, d, f, h-1; R/R′=Pr/tBu, iPr/tBu, iPr/iPr, tBuCH2/tBuCH2, Me3SiCH2/Me3SiCH2, tBu/Me, tBu/iPr, tBu/SiMe3) are formed from the corresponding iminoboranes RB≡NR′ and the neopentylidenetantalum complex [tBuHC=TaCpCl2] (2a) by [2 + 2] cycloaddition. The elimination of HCl from 3b, d, f, h and from the four known azaboratantalacyclobutanes 3a, c, e, g [R/R'equals;Et/tBu, Bu/tBu, Ph/tBu, iBu/iBu] gives the azaboratantalacyclobutenes [-NR′-BR-C(tBu)=TaCpCl-] (4a-h). X-Ray structural analyses of 4e, f show these cyclic carbenetantalum complexes to contain short Ta-C and Ta-N bonds and perhaps some transannular Ta-B interaction. The complex [tBuHC=TaCl3(THF)2] (2b) adds iminoboranes RB≡NtBu with unbranched alkyl groups (R=Et, Pr, Bu) in a 1:2 molar ratio to yield the diazoniadiboratatantalacyclohexadienes 5a-c; the product 5a adopts a non-planar ring structure in the crystal. The 1:2 reaction of 2b with tBuB≡NMes, instead, results in the cyclobutane [-N(Mes)-B(tBu)-N(Mes)-TaCl3(THF)-] (7m).
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/cber.19931260711
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