Base-catalyzed reactions enhanced by solid acids: Amine-catalyzed nitroaldol (Henry) reactions enhanced by silica gel or mesoporous silica SBA-15
作者:Kiyoshi Tanemura、Tsuneo Suzuki
DOI:10.1016/j.tetlet.2017.12.050
日期:2018.1
The reactions of various aldehydes with CH3NO2 catalyzed by Et3N, n-C6H13NH2, and Me2N(CH2)2NH2 were accelerated by the addition of silica gel to givearomatic (aliphatic) β-nitroalcohols, aromatic nitroalkenes, and aromatic 1,3-dinitroalkanes, respectively. Mesoporous silica SBA-15 showed higher activity than silica gel for the synthesis of aromatic nitroalkenes by the reactions of the corresponding
Preparation of indium nitronates and their Henry reactions
作者:Raquel G. Soengas、Rita Acúrcio、Artur M. S. Silva
DOI:10.1039/c4ob01468e
日期:——
Indium nitronates were readily prepared from commercially available nitroalkanes by transmetallation of the corresponding lithium nitronates with indium salts. The Henryreaction of this indium organometallics with aldehydes afforded β-nitroalkanols in moderate to high yields. The use of chiral sugar aldehydes furnished the corresponding carbohydrate-derived β-nitroalkanols with excellent stereoselectivity
Indium-Mediated Reaction of 1-Bromo-1-nitroalkanes with Aldehydes: Access to 2-Nitroalkan-1-ols
作者:Raquel G. Soengas、Amalia M. Estévez
DOI:10.1002/ejoc.201000662
日期:2010.9
A novel method for the preparation of 2-nitroalkan-1-ols by an indium-promoted reaction of bromonitromethane with a variety of aldehydes is reported. The reaction was also performed with 2-bromo-2-nitropropanes to afford 2,2-dialkyl-2-nitroalkan-1-ols. The use of chiral sugar-derived aldehydes furnished the corresponding 2-nitroalkan-1-ols with excellent stereoselectivity. The utility of the novel
Efficient Nitro-Aldol Reaction Using SmI<sub>2</sub>: A New Route to Nitro Alcohols under Very Mild Conditions
作者:José M. Concellón、Humberto Rodríguez-Solla、Carmen Concellón
DOI:10.1021/jo061465w
日期:2006.9.1
A novel method to obtain racemic 1-nitroalkan-2-ols by reaction of bromonitromethane with a variety of aldehydes and promoted by SmI2 is reported. On the basis of these results, the chiral version has also been performed with chiral N,N-dibenzyl amino aldehydes, affording the corresponding enantiopure 3-amino-1-nitroalkan-2-ols with good stereoselectivity.
Indium-Catalyzed Henry-Type Reaction of Aldehydes with Bromonitroalkanes
作者:Raquel Soengas、Artur Silva
DOI:10.1055/s-0031-1290617
日期:2012.4
An economical method to perform the addition of bromonitroalkanes to aldehydes using zinc in the presence of a catalytic amount of indium is established. This procedure affords the corresponding nitroalkanols in good yields and can be easily scaled up to preparative amounts. This indium-catalyzed Henry reaction performs better than the classic base-catalyzed reaction in terms of yields and substrate