27644-02-6Relevant articles and documents
Highly stereoselective allylation of aldehydes with pentacoordinate allylsilicates in hydroxylic media. Discrimination between linear and α-branched alkanals1
Kira,Sato,Sakurai
, p. 257 - 260 (1990)
Allylation of aldehydes with allyltrifluorosilanes in the presence of a wide variety of hydroxy compounds and triethylamine gave the corresponding homoallyl alcohols in regio- and stereospecific manner. Pentacoordinate allylsilicates are suggested as inte
An improved and practical synthesis route to antiproliferative (±)-shikonin and its O-acyl derivatives
Ono, Mana,Abe, Shouki,Higai, Koji,Higashi, Shoko,Saito, Setsuo,Saito, Ryota
, p. 738 - 746 (2020/12/09)
Shikonin and its O-acyl derivatives are attracting increasing levels of attention among medicinal chemists due to their potencies as highly selective cytotoxic agents against cancer cells. However, providing a large number of shikonin-related samples by organic synthesis remains challenging. In the present study, we developed an improved and practical synthesis route to shikonin derivatives by olefin metathesis that has enabled the gram-scale preparation of a prenylated tetramethylnaphthazaline, a key intermediate in the synthesis of shikonin. In addition, a method for the selective cleavage of the acyl protecting groups at the phenolic positions of tri-O-acylated shikonins has been developed that provides concise routes to diverse O-acylshikonin derivatives.
Method for synthesizing polysubstituted alpha, beta unsaturated ketones
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Paragraph 0049; 0056; 0057, (2020/03/06)
The invention particularly relates to a method for synthesizing polysubstituted alpha, beta unsaturated ketones. The method comprises the following steps: 1, adding Ni(cod), an N-heterocyclic carbene ligand, Cs2CO3 and a beta, gamma unsaturated ketone into a non-polar aprotic organic solvent, and mixing to obtain a mixture; 2, adding the mixture obtained in the step 1 into a dried container, reacting for 10-40 hours at the reaction temperature of 120-180 DEG C, and cooling to room temperature after the reaction is finished, so as to obtain a crude product; 3, purifying. According to the method, cheap Ni(cod) is adopted as a catalyst, carbon-carbon bonds are activated by a transition metal, power is provided for the reaction through isomerization of double bonds, the synthesis methodis simple, the substrates are stable and cheap, the reaction is less limited by the substrate, and the substrates are wide in application range.
Catalytic Allylation of Aldehydes Using Unactivated Alkenes
Tanabe, Shun,Mitsunuma, Harunobu,Kanai, Motomu
supporting information, p. 12374 - 12381 (2020/07/14)
Simple feedstock organic molecules, especially alkenes, are attractive starting materials in organic synthesis because of their wide availability. Direct utilization of such bulk, inert organic molecules for practical and selective chemical reactions, however, remains limited. Herein, we developed a ternary hybrid catalyst system comprising a photoredox catalyst, a hydrogen-atom-transfer catalyst, and a chromium complex catalyst, enabling catalytic allylation of aldehydes with simple alkenes, including feedstock lower alkenes. The reaction proceeded under visible-light irradiation at room temperature and with high functional group tolerance. The reaction was extended to an asymmetric variant by employing a chiral chromium complex catalyst.
