Silicon‐ and Tin‐Containing Open‐Chain and Eight‐Membered‐Ring Compounds as Bicentric Lewis Acids toward Anions

Abstract

Herein, we report the syntheses of silicon- and tin-containing open-chain and eight-membered-ring compounds Me2 Si(CH2 SnMe2 X)2 (2, X=Me; 3, X=Cl; 4, X=F), CH2 (SnMe2 CH2 I)2 (7), CH2 (SnMe2 CH2 Cl)2 (8), cyclo-Me2 Sn(CH2 SnMe2 CH2 )2 SiMe2 (6), cyclo-(Me2 SnCH2 )4 (9), cyclo-Me(2-n) Xn Sn(CH2 SiMe2 CH2 )2 SnXn Me(2-n) (5, n=0; 10, n=1, X=Cl; 11, n=1, X=F; 12, n=2, X=Cl), and the chloride and fluoride complexes NEt4 [cyclo- Me(Cl)Sn(CH2 SiMe2 CH2 )2 Sn(Cl)Me⋅F] (13), PPh4 [cyclo-Me(Cl)Sn(CH2 SiMe2 CH2 )2 Sn(Cl)Me⋅Cl] (14), NEt4 [cyclo-Me(F)Sn(CH2 SiMe2 CH2 )2 Sn(F)Me⋅F] (15), [NEt4 ]2 [cyclo-Cl2 Sn(CH2 SiMe2 CH2 )2 SnCl2 ⋅2 Cl] (16), M[Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅Cl] (17 a, M=PPh4 ; 17 b, M=NEt4 ), NEt4 [Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅F] (18), NEt4 [Me2 Si(CH2 Sn(F)Me2 )2 ⋅F] (19), and PPh4 [Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅Br] (20). The compounds were characterised by electrospray mass-spectrometric, IR and (1) H, (13) C, (19) F, (29) Si, and (119) Sn NMR spectroscopic analysis, and, except for 15 and 18, single-crystal X-ray diffraction studies.

From Bidentate Gallium Lewis Acids to Supramolecular Complexes

“…The use of a wide range of Lewis acidic element sites including B, Al, Si, Ga, Ge, In, Sn, Sb, Te, and Hg has allowed the generation of such multifunctional host systems. Lewis acid sites have been integrated in donor‐free cycles or attached to rigid backbones . Defined spatial arrangement of the Lewis acid binding sites enables selectivity in the complexation of Lewis bases.…”

Von zweizähnigen Gallium‐Lewis‐Säuren zu supramolekularen Komplexen

“…Die große Auswahl an Lewis‐sauren Gruppen der Elemente B, Al, Si, Ga, Ge, In, Sn, Sb, Te und Hg ermöglicht die Herstellung verschiedenster multifunktionaler Wirtsysteme. Sie können in donoratomfreien Cyclen oder an starren Grundgerüsten fixiert sein . Der definierte Abstand der Lewis‐sauren Funktionalitäten führt dabei zur selektiven Komplexierung von Lewis‐Basen.…”

Bidentate Lewis Acids Derived from o‐Diethynylbenzene with Group 13 and 14 Functions

“…[19] Synthetic access to tridentate acceptor systems by Lewis acid functionalisation has also been demonstrated. The hydrosilylation of 1,3,5-triethynylbenzene backbones afforded a poly-Lewis acid with large Si•••Si distances [9.708(3), 8.662(3), 10.464(2) Å]. [20] In this work, we report the preparation of a series of directed, bidentate Lewis acids based on a 1,2-diethynylbenzene framework.…”

“…[6] In 1960, pioneering work was presented by Holliday and Massey, having introduced ethyl-bridged diboranes for use in complexation experiments with Lewis-basic guest molecules. [7] These flexible bidentate Lewis acid systems often contained aluminium, [8] tin [9,10] or silicon [10] atoms as Lewis acid functions. The direct attachment of Lewis acid functions (e. g., based on mercury, [11] tin [12] and silicon [13] ) to more rigid backbones such as benzene or naphthalene has also been investigated.…”