54780-61-9Relevant academic research and scientific papers
Rhodium-Catalyzed Enantioconvergent Isomerization of Homoallylic and Bishomoallylic Secondary Alcohols
Huang, Rui-Zhi,Lau, Kai Kiat,Li, Zhaofeng,Liu, Tang-Lin,Zhao, Yu
supporting information, p. 14647 - 14654 (2018/11/06)
We present herein an unprecedented enantioselective isomerization of homoallylic and bishomoallylic secondary alcohols, catalyzed by a commercially available rhodium-complex and a base. This catalytic redox-neutral process provides an effective access to chiral ketones in high efficiency and enantioselectivity, without the use of any stoichiometric reagent or generation of any waste. For the reaction of homoallylic alcohols, this system achieved not only a stereoconvergent access to chiral ketones bearing a β-stereocenter (up to 95%, 86% ee) but also a concomitant oxidative kinetic resolution of the alcohol substrates (S > 20). In the case of bishomoallylic alcohols, an intriguing ligand-induced divergent reactivity was observed. A terminal-to-internal alkene isomerization promoted by Rh/L7 followed by redox isomerization using Rh/BINAP system produced chiral ketones bearing a γ-stereocenter with high yield and enantioselectivity. Mechanistic studies provided strong support for the redox-isomerization pathway with chain walking of the key alkyl-Rh intermediate.
CARBONYL METHYLENATION OF EASILY ENOLIZABLE KETONES
Hibino, Jun-ichi,Okazoe, Takashi,Takai, Kazuhiko,Nozaki, Hitosi
, p. 5579 - 5580 (2007/10/02)
An organometallic reagent prepared from CH2I2, Zn, and TiCl4 is effective for methylenation of the title ketones.
THE METHYLENATION OF ENOLIZABLE KETONES AND ESTERS USING ORGANOTITANIUM CHEMISTRY
Clawson, Leigh,Buchwald, Stephen L.,Grubbs, Robert H.
, p. 5733 - 5736 (2007/10/02)
The titanium methylidene fragment, Cp2Ti=CH2, resulting from Tebbe's reagent, Cp2TiCH2*AlMe2Cl or the β,β-disubstituted metallacycle, Cp2TiCH2C(Me)(n-Pr)CH2, methylenates enolizable acidic ketones and converts α,α-disubstituted ketones into titanium enolates.The reagent reacts selectively with ketones over esters.
STEREOCHEMICAL STUDIES-XXVIII. CONFORMATIONAL EQUILIBRIA OF 2-OCH3, 2-OCOCH3 AND 2-Br DERIVATIVES OF ω-SUBSTITUTED METHYLENECYCLOHEXANES
Zefirov, N. S.,Baranenkov, I. V.
, p. 1769 - 1776 (2007/10/02)
The conformational equilibria of the titled compounds, 10-13, have been determined by 1H NMR and analysed in terms of steric (A(1,3) repulsion, 15) and electronic effects.The conformational equilibria of OMe and Br derivatives depend
Reaction of benzyne with cyclic olefins-II. Ene addition to some cycloalkenes
Mehta,Singh, B.Pal
, p. 2409 - 2412 (2007/10/12)
Addition of benzyne to 1-methylcyclohexene, (+)-carvomenthene, (+)-limonene, α- and β-pinenes and δ3-carene has been investigated. Structures to the ene products formed are assigned on the basis of spectroscopic evidence. Arguments are advanced in favour of a concerted ene mechanism for the addition of benzyne to these olefins.
