82632-40-4Relevant academic research and scientific papers
Rhodium-catalyzed intramolecular hydroacylation of 1,2-disubstituted alkenes for the synthesis of 2-substituted indanones
Yuan, Jing,Liu, Chong,Chen, Yan,Zhang, Zhenfeng,Yan, Deyue,Zhang, Wanbin
, p. 269 - 277 (2018/12/05)
The intramolecular hydroacylation of 1,2-disubstituted alkenes was considered to be a challenging task due to the side reactions resulted from the lack of additional substituent at 1-position and the low activity caused by the steric hindrance of substituent at 2-position, and an asymmetric version has not been considered possible due to problems associated with the racemization of the products. We have partially solved these problems. Catalyzed by an activated diphosphine-Rh complex and reacted in a selected dihalogenated solvent, the intramolecular hydroacylation of o-(2-arylvinyl)benzaldehydes provided the corresponding 2-aryl-1-indanones in high yields, and its asymmetric variant using o-(2-alkylvinyl)benzaldehydes afforded chiral 2-alkyl-1-indanones in high yields and with moderate enantioselectivities.
Selective Divergent Synthesis of Indanols, Indanones, and Indenes via Acid-Mediated Cyclization of (Z)- and (E)-(2-Stilbenyl)methanols and Its Application for the Synthesis of Paucifloral F Derivatives
Jongcharoenkamol, Jira,Chuathong, Patsapon,Amako, Yuka,Kono, Masato,Poonswat, Kasam,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 13184 - 13210 (2018/11/02)
Starting from bromo/iodobenzaldehyde derivatives, the corresponding (Z)- and (E)-(2-stilbenyl)methanols could be prepared in 2-5 steps via Pd-catalyzed cross-coupling reactions (Sonogashira and Heck reactions) followed by aryllithium/aryl Grignard addition. For the (E)-stilbenes, subsequent acid-mediated cyclization using p-TsOH immobilized on silica (PTS-Si) at low temperatures furnished the 2,3-trans-1-indanols with complete stereocontrol at the C2-C3. Further oxidization of the alcohol provided the indanones, which are structurally related to the natural product paucifloral F. At higher temperatures, 1,2- and 2,3-disubstituted indenes could be selectively prepared in good to excellent yields. On the other hand, the (Z)-stilbenes, under similar conditions (PTS-Si), did not give the indanols; only the 1,2-disubstituted indenes could be obtained. To gain further insights into the stereochemistry at C2-C3 for the (Z)-stilbenes, hydride or azide was employed as a nucleophile; the corresponding indane products were obtained with the cis stereochemistry at the C2-C3. Thus, the (Z)- or (E)-olefin geometry of the substrate directed the stereoselective indanyl cyclization to furnish the cis or trans at the C2-C3 ring junction, respectively, while reaction conditions controlled the selectivity of the product types.
