Reaction of [Cp2Ti(Me)(CD2Cl2)]+ (I) with 3,3-dimethyl-1-butene in CD2Cl2 at 205 K produces the α-agostic insertion product [Cp2TiCH2CHMetBu]+ (II), in which the chirality at C(2) induces preferential agostic binding of one of the diastereotopic α-H atoms; subsequent coordination of ethyl ether to II leaves the α-agostic interaction weakened but intact. On warming, II undergoes β-hydrogen elimination and the resulting hydride reacts further with excess 3,3-dimethyl-1-butene to form the β-agostic species [Cp2TiCH2CH2tBu]+. NMR data and calculated (DFT) energies support the assignments.
α- and β-Agostic Alkyl–Titanocene Complexes / Dunlop Brière, A. F.; Budzelaar, Petrus Henricus Maria; Baird, M. C.. - In: ORGANOMETALLICS. - ISSN 0276-7333. - 31:5(2012), pp. 1591-1594. [10.1021/om3001197]
α- and β-Agostic Alkyl–Titanocene Complexes
BUDZELAAR, Petrus Henricus Maria;
2012
Abstract
Reaction of [Cp2Ti(Me)(CD2Cl2)]+ (I) with 3,3-dimethyl-1-butene in CD2Cl2 at 205 K produces the α-agostic insertion product [Cp2TiCH2CHMetBu]+ (II), in which the chirality at C(2) induces preferential agostic binding of one of the diastereotopic α-H atoms; subsequent coordination of ethyl ether to II leaves the α-agostic interaction weakened but intact. On warming, II undergoes β-hydrogen elimination and the resulting hydride reacts further with excess 3,3-dimethyl-1-butene to form the β-agostic species [Cp2TiCH2CH2tBu]+. NMR data and calculated (DFT) energies support the assignments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
