Synthetic Uses of Chlorotitanium(IV) Triisopropoxide in C-C(N) Bond Formation

Introduction

Chlorotitanium(IV) isopropoxide, ClTi(Oi-Pr)₃, is a Lewis acid utilized in various synthetic procedures for carbon-carbon (or nitrogen) bond constructions. Its preparation involves the mixing of three equivalents of tetraisoprop­oxytitanium and one equivalent of titanium(IV) chloride at 0 ˚C under a nitrogen atmosphere. Vacuum distillation of the crude product furnishes a syrupy liquid which turns into a solid at room temperature. It is soluble in n-pentane, toluene, THF and CH₂Cl₂; it is moisture-sensitive but can be kept under nitrogen for several months. [¹] The reagent is used as a starting material for the synthesis of versatile alkyl- and aryltriisopropoxytitanium compounds that are more chemo- and stereoselective as compared to Grignard reagents. [¹] ^,²

Scheme 1 Chemical preparation of ClTi(Oi-Pr)3

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