84365-33-3Relevant academic research and scientific papers
Organotin(IV) compounds derived from 2-Me2NC6H4CH2Li and its chiral α-Me3Si derivative. X-ray structure of pentacoordinate [{2-(dimethylamino)phenyl}(trimethylsilyl)methyl-C,N]methylphenyltin bromide having a chiral Sn center
Jastrzebski, Johann T. B. H.,Van Koten, Gerard,Knaap, Christopher T.,Schreurs, Antoine M. M.,Kroon, Jan,Spek, Anthony L.
, p. 1551 - 1558 (2008/10/08)
A series of triorganotin halides, RR′SnBr(C-N), and a series of tetraorganotin compounds, R3Sn(C-N), have been synthesized in which C-N is either monoanionic 2-Me2NC6H4CH2- or novel, monoanionic 2-Me2NC6H4CH(SiMe3)-. 1H and 13C NMR data indicate that the tin center in the R3Sn(C-N) compounds is tetracoordinate whereas this center in the RR′SnBr(C-N) derivatives is pentacoordinate as a result of intramolecular Sn-N coordination. Pentacoordination in a trigonal-bipyramidal manner with axial N and Br atoms has also been established by the X-ray structure determination of 2-Me2NC6H4CH(SiMe3)-SnMePhBr (4c): C19H28BrNSiSn; monoclinic; P21/n, a = 13.085 (4) ?, b = 16.127 (5) ?, c = 10.437 (3) ?; β = 99.88 (2)°; V = 2170 (1) ?; Z = 4; μ(Mo Kα) = 29.4 cm-1; R = 0.0307 for 3185 [I ≥ 2.5σ(I)] reflections. Compound 4c contains two chiral centers, which are formed stereospecifically during the reaction of 2-Me2NC6H4CH(SiMe3)Li with PhMeSnBr2 and have either the RC, RSn or the SC, SSn combination of configurations at the benzylic C and five-coordinate Sn centers. The structure shows that the chelate ring conformation is such that it places the bulky Me3Si substituent both out of the plane of the aryl ring and, furthermore, at the side of the less bulky methyl ligand. It is suggested that the unusual high configurational stability of the RR′SnBr(C-N) compounds arises from the rigidity of the 2-Me2NC6H4CH(Z)- ligand which holds the 2-Me2N group in close proximity of the tin center. If Z is the bulky SiMe3 group also, the SnR2Br grouping is locked in a fixed position with respect to the N donor site.
