- Method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and diphosphine ligand used in method
-
The invention discloses a method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and a diphosphine ligand used in the method. According to the invention, indole-substituted phosphoramidite diphosphine ligand which is stable in air and insensitive to light is synthesized by utilizing a continuous one-pot method, and the indole-substituted phosphoramidite diphosphine ligand and a rhodium catalyst are used for jointly catalyzing to successfully achieve a hydroformylation reaction of aromatic terminal alkyne and terminal conjugated eneyne under the condition of synthesis gas for the first time, so that an olefine aldehyde structure compound can be rapidly and massively prepared, and particularly, a polyolefine aldehyde structure compound which is more difficult to synthesize in the prior art can be easily prepared and synthesized, and a novel method is provided for synthesis and modification of drug molecules, intermediates and chemical products.
- -
-
Paragraph 0168-0171
(2021/05/29)
-
- Palladium-catalyzed reactions of 3-substituted methylenecyclopropanes
-
Pd-catalyzed reactions of 3-substituted methylenecyclopropanes (MCPs), in which the substituents can be either hydroxymethyl or formyl, have been thoroughly investigated in the presence or absence of an acid source. It was found that the Pd-catalyzed reactions of methylenecyclopropylcarbinols (Z)-1 in the presence of acetic acid, acetic acid 2-methylene-but-3-enyl esters 4 can be formed in moderate yields. It was also found that Pd alone can catalyze the isomerization of methylenecyclopropylcarbinols (E)-1 in the absence of an acid source to form pent-4-enals 3. The Pd-catalyzed reactions of methylenecyclopropanecarbaldehydes 5 were also carried out in the presence of acetic acid. It was found that when (E)-5 was used as the substrate, the isomerized product, penta-2,4-dienal 6, could be obtained in good to high yields, whereas the use of (Z)-5 gave 2-(3-formylpenta-2,4-dienylidene) cyclopropanecarbaldehyde 7 in moderate to good yields. Plausible mechanisms for all these transformations have been discussed on the basis of the obtained results and control experiments. Copyright
- Shao, Li-Xiong,Li, Jia,Wang, Bao-Yu,Shi, Min
-
supporting information; experimental part
p. 6448 - 6453
(2011/02/21)
-
- New Functionalized Horner-Wadsworth-Emmons Reagents: Useful Building Blocks in the Synthesis of Polyunsaturated Aldehydes. A Short Synthesis of (+/-)-(E,E)-Coriolic Acid
-
The new Horner-Wadsworth-Emmons reagents 4 and 5 transform carbonyl compounds into 2,4-pentadienals and 3-methyl-2,4-pentadienals, respectively.Reagent 4 gives good yields of the desired products with a variety of aldehydes and ketones; reagent 5 generally gives good yields with aldehydes, but gives lower yields with ketones.The reactions proceed under mild conditions and give the products as predominantly 2E,4E isomers, with moderate to good stereoselectivity.In general, pure samples of the 2E,4E-dienals can be obtained after chromatography.Reagents 4 have been used in the key step in a short synthesis of (+/-)-13-hydroxy-9(E),11(E)-octadecanoic acid ((E,E)-coriolic aicd, 45).
- Kann, Nina,Rein, Tobias,Akermark, Bjoern,Helquist, Paul
-
p. 5312 - 5323
(2007/10/02)
-