215256-91-0Relevant academic research and scientific papers
Isomerizations on silica gel: Synthesis of allenyl ketones and the first Nazarov cyclizations of vinyl allenyl ketones
Stephen,Hashmi,Bats, Jan W.,Choi, Ji-Hyun,Schwarz, Lothar
, p. 7491 - 7494 (1998)
Dess-Martin oxidation followed by the chromatographic workup of crude, terminal propargyl ketones 5 on silica gel directly leads to terminal allenyl ketones 6. When the other substituent on 5 was electron-rich, 7 was observed as side-product. If the other substituent on 5 was electron-poor, the isomeric 1-propynyl ketone 8 was the side-product. Chromatography of the crude propargyl vinyl ketones 10 on silica gel delivers the products of a Nazarov cyclization.
Synthesis of vinylic sulfones in aqueous media
Goh, Jeffrey,Maraswami, Manikantha,Loh, Teck-Peng
, p. 1060 - 1065 (2021/02/16)
A green method for the sulfination of allenic carbonyl compounds to access a wide variety of vinylic sulfones is developed. This reaction works in aqueous media under very mild conditions. This reaction is atom economic. A wide variety of vinylic sulfones could be obtained in moderate to excellent yields with wide functional group tolerance. The efficiency of this method is demonstrated in some reactions where the desired products can be isolated by filtration.
Synthesis of allenyl ketones and their palladium-catalyzed cycloisomerization/dimerization: Approaching the limits
Hashmi, A. Stephen K.,Choi, Ji-Hyun,Bats, Jan W.
, p. 342 - 357 (2007/10/03)
The preparation of several new allenyl ketones 1a-j and 1o-q is reported. In the case of allenyl ketones with nucleophilic groups in the side-chain like 1k-m, the material polymerized during the purification procedure; with the dialkyl thioether In the product of a Pummerer isomerization, the acetoxymethyl alkyl thioether, 11 was formed. Depending on the route to 1 sometimes either the acetate adducts 8 and the 1-propynyl ketones 9 or the dipropargyl and propargyl allenyl carbinol 14 and 15 were observed as side-products. Good yields of the sensitive aryl γ-halogen-allenyl ketones 23a and 23b were obtained by a new synthetic route, on the other hand the aryl γ-silylallenyl ketone 23c was readily desilylated. Subjecting the new allenyl ketones to the PdCl2(MeCN)2 catalyst provided the 2-substituted furans 2 and the 2,4-disubstituted furans 3 in most cases. The yields and ratios of these products strongly depended on the nature of the groups being present. With the aryl thioether and the γ-halogen allenyl ketones the palladium-catalyzed reaction failed. Detailed structural information about the new products was provided by the X-ray structure analyses of the p-acetamidophenyl propargyl carbinol 6g and the 2-aryl-4-(1-methyl-3-aryl-3-oxo-propen-1-yl furan 3h. Wiley-VCH Verlag GmbH, 1999.
