737758-48-4Relevant academic research and scientific papers
Manganese-Catalyzed Stereospecific Hydroxymethylation of Alkyl Tosylates
Shenouda, Hannah,Alexanian, Erik J.
supporting information, p. 9268 - 9271 (2019/11/19)
The development of a stereospecific hydroxymethylation of alkyl tosylates using an inexpensive, first-row catalyst is described. The transformation proceeds under mild conditions with low pressure to deliver homologated alcohols as products. Chiral, nonracemic β-branched primary alcohols are obtained with high enantiospecificity from easily accessed secondary alkyl substrates. Simple modification of the reaction system also permits access to α-d2 alcohols. These studies use anionic metal carbonyl catalysis to access a synthetic equivalent of the challenging hydroxymethyl anion from carbon monoxide.
Cobalt-Catalyzed Carbonylative Cross-Coupling of Alkyl Tosylates and Dienes: Stereospecific Synthesis of Dienones at Low Pressure
Sargent, Brendon T.,Alexanian, Erik J.
supporting information, p. 12438 - 12440 (2017/09/25)
Despite advances in organometallic cross-coupling of alkyl electrophiles, there are few stereoselective reactions of chiral, nonracemic substrates. Herein we report a stereospecific carbonylative coupling of alkyl tosylates and dienes producing enantioenriched dienones. This catalytic process proceeds under low pressure and mild conditions using a simple cobalt catalyst and extends to diverse tosylate and diene coupling partners. The transformation constitutes a unique, convergent approach to the asymmetric synthesis of valuable carbonyl compounds from easily accessed starting materials.
"Chiral perturbation factor" approach reveals importance of entropy term in stereocontrol of the 2,4-pentanediol-tethered reaction
Tei, Takahiro,Sato, Yasuhiro,Hagiya, Kazutake,Tai, Akira,Okuyama, Tadashi,Sugimura, Takashi
, p. 6593 - 6598 (2007/10/03)
The stereocontrol mechanism of the 2,4-pentanediol (PD)-tethered reaction was studied in detail using a reaction system consisting of phenyl and rhodium carbenoid moieties. Different tethers were examined to analyze the effects of the methyl groups on the PD tether. Among the reactions with these tethers, the PD tether achieves an unmeasurably high stereoselectivity in a diastereomeric ratio of >500. Another tether showing a high but measurable stereoselectivity in a ratio of 41 is mostly controlled by the entropy term. To clarify the role of the methyl groups on the chiral tethers, which are the origin of the stereocontrol, the "chiral perturbation factor" is introduced. This parameter is defined as the rate of a chiral reaction relative to that of an a chiral reference reaction. By analyzing the temperature dependence of the chiral perturbation factors for different chiral-tethered reactions, high potentials of the PD-tethered reaction in its stereocontrol are concluded to be due to the entropy term.
