869012-03-3Relevant articles and documents
Titanium-mediated addition of grignard reagents to acyl cyanohydrins: Aminocyclopropane versus 1,4-diketone formation
Setzer, Paul,Forcher, Gwenael,Boeda, Fabien,Pearson-Long, Morwenna S. M.,Bertus, Philippe
, p. 171 - 180 (2014/01/06)
The 1,2-dianion reactivity of the reagent generated from EtMgBr and titanium isopropoxide was illustrated when N-acyl cyanohydrins were used as substrates (>20 examples), giving both aminocyclopropane derivatives and 1,4-dicarbonyl compounds. When the reaction was performed in diethyl ether, 5-hydroxy-1,4-diketones were the main product. Under specific conditions (use of tetrahydrofuran and a bulky carboxylic moiety), the cyclopropane derivatives were obtained in good yields. The observed dichotomy may be explained by a ring-opening of the five-membered titanacycle intermediate followed by a nonselective acyl addition. The 1,2-dianion reactivity of the reagent generated from EtMgBr and Ti(OiPr)4 was illustrated when N-acyl cyanohydrins were used as substrates (>20 examples). When the reaction was performed in diethyl ether, 1,4-diketones were mainly isolated. Under certain conditions, cyclopropane derivatives were also obtained in good yields. A mechanism rationalizing this dichotomy is presented. Copyright
Studies on the titanium-catalyzed cyclopropanation of nitriles
Laroche, Christophe,Harakat, Dominique,Bertus, Philippe,Szymoniak, Jan
, p. 3482 - 3487 (2007/10/03)
The Ti-mediated reaction of Grignard reagents with nitriles was investigated with sub-stoichiometric amounts of titanium isopropoxide. Cyanoesters were converted to spirocyclopropanelactams in good yields using as low as 0.05 eq of Ti(OiPr)sub
