Synthesis of Directed, Tridentate Lewis Acids Based on a Trisilacyclohexane‐Backbone via Hydrosilylation

Abstract

Based on a semiflexible trisilacyclohexane framework a series of directed, tridentate Lewis acids were synthesized by hydrosilylation using various (chloro)methylsilanes. The axial alignment of the three electron deficient functions in one spatial direction allows creating poly-Lewis acids with chalice-like cavities. The directed, tridentate poly-Lewis acids were obtained in quantitative yields and characterized by multinuclear NMR spectroscopy, CHN analysis and X-ray diffraction experiments. The Lewis acidity of the introduced silicon functions was quantified and classified using the Gutmann-Beckett method.

Syntheses and Conformations of a Trinuclear Gold(I) System Based on a Triethinyl‐trisilacyclohexane Scaffold

“…Combined with the often cited ability of trisilacyclohexanes to invert their ring conformation, these results underscore their ability to create two differently sized cavities, especially when using terminal groups with strong London dispersion attraction. [14,[20][21][22] Since 4 c shows only the allequatorial conformation in the crystal structure, we assume that the conformational behavior is also phase dependent.…”

Hydroalumination of 1,8-Diethynylanthracenes–Al-based Bis-Lewis-Acids and their Isomerization and Complexation Behavior

“…The newly formed C�C double bond also protrudes out of the plane of carbon atoms of the backbone. Through this protrusion, one Bis substituent is partially located beneath the anthracene backbone and one methyne hydrogen atom [H (32)] is pointing toward the center of the closest aromatic unit with a distance [d(H32•••C centroid )] of about 2.6 Å. The Al atom is planar three-coordinate [sum of the angles 360.0(1)°].…”

“…Within the field of main group chemistry, compounds such as frustrated Lewis pairs − or poly-Lewis acids (PLAs) containing main group elements as reactive sites–including octet compliant metallacyclo-compounds − along with systems of low-coordinate, electron-deficient Lewis centers anchored to organic backbones − –have been of special interest in the last decades, since most main group (semi-)metals are more abundant and the utilized compounds are often less toxic than analogous transition metal-based molecules. PLAs containing main group elements can be used in small molecule recognition, ,,,− anion sensing, ,,,,,,,− or in catalysis. ,− ,, This is why we focus on PLAs containing group 13 elements such as aluminum, boron, or gallium as active sites.…”