3240-29-7Relevant articles and documents
Nickelocene-Lithium Aluminum Hydride: A Versatile Desulfurization Reagent
Chan, Man-Chor,Cheng, Kwok-Man,Ho, Kim Man,Ng, Chi Tat,Yam, Tsz Man,et al.
, p. 4466 - 4471 (1988)
A new homogeneous organonickel reagent prepared from nickelocene and LiAlH4 has been shown to be effective for the reduction of the carbon-sulfur bonds of thiols, thioethers, sulfoxides, and sulfones to the corresponding carbon-hydrogen bonds.Functional groups such as isolated double bonds, esters, and carbonyls as well as halides remain intact under the reaction conditions.Preliminary studies on the nature of the reagent and the mechanism for the reaction have been carried out by employing deuterium labeling experiments and spectroscopic methods.Metal hydridic species may play an important role in these reactions.The reagent can also be used to reduce the carbon-carbon double bond of conjugate enones and catalyze hydrogenation of carbon-carbon multiple bonds.A comparison of the reaction behavior of this newly developed reagent with that of Raney nickel is discussed.
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Wagner,Sedon
, p. 1927 (1978)
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Catalytic Diverse Radical-Mediated 1,2-Cyanofunctionalization of Unactivated Alkenes via Synergistic Remote Cyano Migration and Protected Strategies
Wang, Na,Li, Lei,Li, Zhong-Liang,Yang, Ning-Yuan,Guo, Zhen,Zhang, Hong-Xia,Liu, Xin-Yuan
, p. 6026 - 6029 (2016)
A catalytic radical protocol for 1,2-cyanofunctionalization of unactivated alkenes involving remote cyano migration triggered by addition of diverse carbon- and heteroatom-centered radicals to alkenes has been developed. This powerful strategy provides a
Preparation of Primary and Secondary Dialkylmagnesiums by a Radical I/Mg-Exchange Reaction Using sBu2Mg in Toluene
Knochel, Paul,Lutter, Ferdinand H.,Sunagatullina, Alisa S.
, (2022/02/16)
The treatment of primary or secondary alkyl iodides with sBu2Mg in toluene (25–40 °C, 2–4 h) provided dialkylmagnesiums that underwent various reactions with aldehydes, ketones, acid chlorides or allylic bromides. 3-Substituted secondary cyclohexyl iodides led to all-cis-3-cyclohexylmagnesium reagents under these exchange conditions in a highly stereoconvergent manner. Enantiomerically enriched 3-silyloxy-substituted secondary alkyl iodides gave after an exchange reaction with sBu2Mg stereodefined dialkylmagnesiums that after quenching with various electrophiles furnished various 1,3-stereodefined products including homo-aldol products (99 % dr and 98 % ee). Mechanistic studies confirmed a radical pathway for these new iodine/magnesium-exchange reactions.
Nickel-catalyzed remote hydrosilylation of unconjugated enones with bulky triphenylsilane
Chen, Xue,Wang, Zhen,Zhou, Jinyong,Liu, Yunkui,Jin, Hongwei,Zhou, Bingwei
supporting information, p. 8021 - 8024 (2021/10/04)
Herein we describe a nickel-catalyzed remote hydrosilylation of unconjugated enones with bulky triphenylsilane. A range ofZ-silyl enol ethers are obtained as major isomers due to the process of nickel triggered alkene isomerization. Notably, some specific
α- And β-Functionalized Ketones from 1,3-Dienes and Aldehydes: Control of Regio- And Enantioselectivity in Hydroacylation of 1,3-Dienes
Parsutkar, Mahesh M.,Rajanbabu, T. V.
supporting information, p. 12825 - 12835 (2021/08/30)
Ketones are among the most widely used intermediates in organic synthesis, and their synthesis from inexpensive feedstocks could be quite impactful. Regio- and enantioselective hydroacylation reactions of dienes provide facile entry into useful ketone-bearing chiral motifs with an additional latent functionality (alkene) suitable for further elaboration. Three classes of dienes, 2- or 4-monosubstituted and 2,4-disubstituted 1,3-dienes, undergo cobalt(I)-catalyzed regio- and enantioselective hydroacylation, giving products with high enantiomeric ratios (er). These reactions are highly dependent on the ligands, and we have identified the most useful ligands and reaction conditions for each class of dienes. 2-Substituted and 2,4-disubstituted dienes predominantly undergo 1,2-addition, whereas 4-substituted terminal dienes give highly enantioselective 4,1- or 4,3-hydroacylation depending on the aldehyde, aliphatic aldehydes giving 4,1-addition and aromatic aldehydes giving 4,3-addition. Included among the substrates are feedstock dienes, isoprene (US$1.4/kg) and myrcene (US$129/kg), and several common aldehydes. We propose an oxidative dimerization mechanism that involves a Co(I)/Co(III) redox cycle that appears to be initiated by a cationic Co(I) intermediate. Studies of reactions using isolated neutral and cationic Co(I) complexes confirm the critical role of the cationic intermediates in these reactions. Enantioselective 1,2-hydroacylation of 2-trimethylsiloxy-1,3-diene reveals a hitherto undisclosed route to chiral siloxy-protected aldols. Finally, facile syntheses of the anti-inflammatory drug (S)-Flobufen (2 steps, 92% yield, >99:1 er) and the food additive (S)-Dihydrotagetone (1 step, 83% yield; 96:4 er) from isoprene illustrate the power of this method for the preparation of commercially relevant compounds.
