536696-51-2Relevant academic research and scientific papers
Highly diastereoselective hydrosilylations of allylic alcohols
McLaughlin, Mark G.,Cook, Matthew J.
supporting information, p. 3501 - 3504 (2014/03/21)
The highly syn-selective hydrosilylation of allylic alcohols was developed which, following oxidation, provided 1,3 alcohols containing two contiguous stereocentres. Through judicious choice of silane the complementary anti-selective hydrosilylation was a
Manganese(III) acetate mediated oxidative radical cyclizations. Toward vicinal all-carbon quaternary stereocenters
Logan, Angus W.J.,Parker, Jeremy S.,Hallside, Michal S.,Burton, Jonathan W.
supporting information; experimental part, p. 2940 - 2943 (2012/08/28)
Manganese(III) acetate mediated oxidative radical cyclizations have been used to synthesize a range of densely functionalized and sterically congested cyclopentane-lactones. A number of the resulting lactones contain vicinal all-carbon quaternary stereocenters adjacent to a tertiary benzylic stereocenter and are formed with high levels of stereocontrol.
Diastereoselective hydroformylation of 2-substituted allylic o-DPPB-Esters-On the origin of 1,2-asymmetric induction
Breit, Bernhard,Heckmann, Golo,Zahn, Stephan K.
, p. 425 - 434 (2007/10/03)
2-Substituted secondary alcohol o-DPPB esters (o-DPPB = orthodiphenylphosphanylbenzoyl) have been prepared and their o-DPPB-directed diastereoselective hydroformylation examined. It was found that the diastereoselectivity increased as a function of the steric demand of the substituents both at the stereogenic center and in the alkene 2-position. Hydrolytic cleavage of the o-DPPB group afforded - via the lactols 29 - the corresponding lactones 30, the relative configurations of the vicinal stereogenic centers of which were ascertainable by 2D-NOESY spectroscopy. In addition, a crystal structure analysis of the hydroformylation product 2d provided further confirmation of the relative configuration. Replacement of the ester carbonyl group of the o-DPPB by a methylene unit resulted in significantly worse diastereoselectivity in the course of the hydroformylation (34→35), which indicates a decisive role for the ester carbonyl function. All the experimental observations were combined in a model of the origin of the 1,2-asymmetric induction during the title reaction. The key feature is the consideration of diastereomeric trigonal-bipyramidal rhodium-hydrido-olefin complexes I and II, capable on the basis of the Hammond postulate of acting as good models for the transition states of the selectivity-determining hydrometalation step. Investigation of these complexes by force-field methods indicated good correlation between theoretically predicted and experimentally determined diastereoselectivities.
