Synthetic transformations mediated by the combination of titanium(IV) alkoxides and Grignard reagents: selectivity issues and recent applications. Part 2: Reactions of alkenes, allenes and alkynes

Stereoselective Alkylation of Allylic Alcohols: Tandem Ethylation and Functionalization

“…(1); El = H]. [4][5][6] The synthetic utility of the low-valent titanium (Kulinkovich reagent) [4] mediated alkylation would be greatly enhanced by an in situ introduction of a functionalized side chain (El ¼ 6 H). We report herein a stereoselective alkylation reaction of allylic alcohols by trapping of the presumed alkyltitanium intermediates with suitable electrophiles.…”

Synthesis of 1,4-Diketones via Titanium-Mediated Reductive Homocoupling of α-Haloketones

“…Titanocyclopropanes generated from cyclohexylmagnesium bromide have demonstrated diminished nucleophilicity in other systems but had little effect on the homocoupling leading to a slight decrease in yield (Table 1, entry 10). 14 It has also been demonstrated that the disproportionation reaction to form titanium(III) intermediates is favored when the titanium and Grignard reagents are premixed and heated. 10 For this reaction, it surprisingly only led to a reduced yield (Table 1, entries 11 and 12).…”

“…Finally, the homocoupling was compatible with a variety of heteroaromatic compounds including pyridine 26, naphthalene 28, benzofuran 30, and thiophene 32 (Table 2, entries [11][12][13][14]. While the yields of these reactions vary, it is noteworthy that these substrates have not been accessible via other homodimerization procedures.…”

Synthesis and Electrochemical Properties of Fullerenylstyrenes

“…Considering published data, − we proposed a probable mechanism of formation of monoarylalkene fullerene derivatives in the reaction of C 60 with terminal arylacetylenes and EtMgBr in the presence of Ti­(O i -Pr) 4 (Scheme ).…”