26164-17-0Relevant academic research and scientific papers
Enantioselective hydrogen transfer reactions from chiral binaphthyl variants of tin hydrides to prochiral radicals
Blumenstein, Michael,Lemmler, Matthias,Hayen, Ahlke,Metzger, Juergen O.
, p. 3069 - 3077 (2003)
Enantioselective, reagent-controlled radical reductions of prochiral alkyl radicals, mediated by binaphthyl variants of tin hydrides can be carried out in a highly selective fashion: a maximum selectivity of 68% e.e. was reached. Temperature, solvent, Lewis acid and substituent effects are selectivity-controlling elements. The reactions can be conducted catalytically with 1 mol% of chiral information and excess NaCNBH3.
Catalytic Asymmetric C-H Activation of Alkanes and Tetrahydrofuran
Davies, Huw M. L.,Hansen, Tore,Churchill, Melvyn Rowen
, p. 3063 - 3070 (2007/10/03)
Rhodium carbenoids derived from methyl aryldiazoacetates are capable of effective catalytic asymmetric C-H activation of a range of alkanes and tetrahydrofuran by a C-H insertion mechanism. Dirhodium tetrakis(S-(N-dodecylbenzenesulfonyl)prolinate) (Rh2(S-DOSP)4) catalyzed decomposition of methyl aryldiazoacetates in the presence of alkanes results in intermolecular C-H insertions with good control of regioselectivity, diastereoselectivity, and enantioselectivity. The carbenoids derived from methyl aryldiazoacetates are considerably more chemoselective than carbenoids derived from diazoacetates. They strongly favor C-H insertions into secondary and tertiary sites. Formation of side products due to carbene dimerization is not a major problem with rhodium carbenoids derived from aryldiazoacetates.
Enantioselectivity of the transfer of hydrogen atoms to acyclic prochiral carbon-centred radicals using chiral tin hydrides
Schwarzkopf, Kay,Blumenstein, Michael,Hayen, Ahlke,Metzger, Jürgen O.
, p. 177 - 181 (2007/10/03)
Racemic α-bromo esters 2 have been reduced via prochiral radicals 5 with low to moderate enantioselectivities using chiral tin hydrides 1 with a stereogenic tin atom containing chiral 2-[(1-dimethylaminoalkyl)phenyl] ligands. The tin hydrides 1 were mixtures of diastereomers. It could be shown that the minor diastereomer of tin hydrides 1a and 1b reacts with good enantioselectivity whereas the major diastereomer reacts almost unselectively. The observed enantioselectivities are also strongly influenced by steric effects of the substituents attached to the radical centre.
