Activation reactions of 1,1-dialkoxoalkanes and unsaturated O-donors by titanium tetrafluoride

The reactivity of TiF4 with a variety of non cyclic 1,1-dialkoxoalkanes [CH2(OR)2, R = Me, Et, Me2C(OMe)2, MeCH(OEt)2, ClCH2CH(OEt)2, CH(OMe)3, PhCCCH(OEt)2], 1,3-dioxolane, N2CHCO2Et and 1,2-epoxybutane has been investigated. Activation, including fragmentation and/or rearrangement of the organic moiety, has been observed at room temperature in some cases; it generally occurs unselectively via C−O bond fission and the formation of new C−O, C−H and C−C bonds. Small differences in the structure of the organic substrate may determine significant differences in the reactivity with TiF4.