Indium Tribromide as a Highly Efficient and Versatile Catalyst for Chemoselective Synthesis of Acylals from Aldehydes under Solvent-Free Conditions
作者:Yong-Mei Wang、Liang Yin、Zhan-Hui Zhang、Mei-Li Pang
DOI:10.1055/s-2004-829549
日期:——
A mild and efficient method has been developed for the chemoselective preparation of acylals from aldehydes in the presence of catalytic amounts (0.01-1.0 mol%) of InBr3 under solvent-free conditions in very good to excellent yields.
Supported N-propylsulfamic acid onto Fe3O4 magnetic nanoparticles as a reusable and efficient nanocatalyst for the protection/deprotection of hydroxyl groups and protection of aldehydes
作者:Amin Rostami、Bahman Tahmasbi、Fatemeh Abedi
DOI:10.1007/s11164-015-2239-3
日期:2016.4
nanocatalyst has been reported for the tetrahydropyranylation/depyranylation of a wide variety of alcohols and phenols by changing the solvent medium. Also, the protection of aldehydes as acylals using Ac2O in the presence of catalytic amount MNPs-PSA in good to high yields at room temperature undersolvent-freeconditions is described. After completing the reaction, the catalyst was easily separated from the
已经报道了负载在Fe 3 O 4磁性纳米颗粒(MNPs-PSA)上的 N- 丙基氨基磺酸作为一种有效的和可磁重复使用的纳米催化剂,可以通过改变溶剂介质将其用于多种醇和酚的四氢吡喃基化/脱吡喃基化。此外,还描述了在无溶剂条件下,在室温下,在催化量的MNPs-PSA存在下,使用Ac 2 O以高至高收率保护醛作为酰基的醛。反应完成后,借助外部磁场可以很容易地将催化剂从反应混合物中分离出来,并连续使用几次,而不会明显降低其催化效率。
2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO) as a Versatile, Efficient, and Chemoselective Catalyst for the Acetalization and Transacetalization of Carbonyl Compounds, the Preparation of Acetonides from Epoxides and Acylals (1,1-Diacetates) from Aldehydes
The efficient and chemoselective preparation of acetals and ketals from carbonyl compounds, transacetalization reactions, the conversion of epoxides to acetonides, and the preparation of acylals from aldehydes in the presence of catalytic amounts of 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TABCO) are described.
P4VP-H<sub>2</sub>SO<sub>4</sub>-Catalyzed Chemoselective Protection of Aldehydes to Acylal Along with Deprotection Reactions
作者:Papia Dutta、Parishmita Sarma、Ruli Borah
DOI:10.1080/00397911.2011.635258
日期:2013.5.15
heterogeneous catalyst for the chemoselective synthesis of 1,1-diacetates(acylal) from aldehydes in dichloromethane at room temperature within a few minutes. The protection of salicyaldehyde generated an anhydro-dimer as single product under similar reaction conditions. The catalyst is equally applicable for the deprotection of acylal in acetonitrile. The catalyst was prepared by the wet impregnation technique
A novel heterogeneous efficient procedure has been developed for the chemoselective synthesis of acylals (1,1-diacetates) under solvent-free conditions. A novel catalyst prepared by the sulfuricacidcatalyzed copolymerization of p-toluenesulfonic acid and paraformaldehyde displays extremely high activities for the title reactions, affording average yields over 90% within several minutes. A comparative