1004-09-7Relevant academic research and scientific papers
Kinetic resolution of secondary alcohols using proline-derived bicyclic iminium salts
Aitken, R. Alan,Ali, Karamat,Mesher, Shaun T. E.
, p. 4179 - 4182 (1997)
The proline-derived bicyclic iminium salt 3 can be used to bring about kinetic resolution in its reaction with salts of secondary alcohols to give the corresponding methyl sulfides. Reaction proceeds most efficiently with sodium 1-phenylethoxide in toluene at RT where either 3 or the benzyl salt 14 give e.e.s of 21-25% and changing the heteroatoms present in the sails, the metal cation used and the solvent and temperature all give similar or lower selectivity.
Catalytic Regioselective Olefin Hydroarylation(alkenylation) by Sequential Carbonickelation-Hydride Transfer
Liu, Chen-Fei,Luo, Xiaohua,Wang, Hongyu,Koh, Ming Joo
supporting information, p. 9498 - 9506 (2021/07/19)
Alkene hydrocarbofunctionalization represents one of the most important classes of chemical transformations, but related branched-selective examples with unactivated olefins are scarce. Here, we report that catalytic amounts of a dimeric Ni(I) complex and an exogenous alkoxide base promote Markovnikov-selective hydroarylation(alkenylation) of unactivated and activated olefins using organo bromides or triflates derived from widely available phenols and ketones. Products bearing aryl- and alkenyl-substituted tertiary and quaternary centers could be isolated in up to 95% yield and >99:1 regioisomeric ratios. Contrary to previous dual-catalytic methods that rely on metal-hydride atom transfer (MHAT) to the olefin prior to carbofunctionalization with a cocatalyst, our mechanistic evidence points toward a nonradical reaction pathway that begins with site-selective carbonickelation across the C═C bond followed by hydride transfer using alkoxide as the hydride source. Utility of the single-catalyst protocol is highlighted through the synthesis of medicinally relevant scaffolds.
