{[[K.18-Crown-6]Br3}n: A tribromide catalyst for the catalytic protection of amines and alcohols
作者:Gholamabbas Chehardoli、Mohammad Ali Zolfigol、Fateme Derakhshanpanah
DOI:10.1016/s1872-2067(12)60644-5
日期:2013.9
[K.18-Crown-6]Br3}n, a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic) and aromatic, and primary and secondary amines and also various TMS-ethers and THP-ethers. The simple separation of the catalyst
Magnetic nanoparticle-supported DABCO tribromide: a versatile nanocatalyst for the synthesis of quinazolinones and benzimidazoles and protection/deprotection of hydroxyl groups
supported on magnetic Fe3O4 nanoparticles (MNPs-DABCO tribromide) as a novel heterogeneous tribromide type compound was found to be an efficient and reusable nanocatalyst for the one-pot synthesis of 2-arylquinazolin-4(3H)-ones and 2-aryl-1H-benzo[d]imidazoles through oxidative cyclization of aldehydes with 2-aminobenzamides and 1,2-phenylenediamine, respectively. Also, MNPs-DABCO tribromide catalyzed tr
发现一种新型的非均相三溴化物类型化合物,负载在磁性Fe 3 O 4纳米颗粒上的1,4-二氮杂双环[2.2.2]辛烷三溴化物(MNPs-DABCO三溴化物)是一种高效且可重复使用的纳米催化剂,可用于一锅法合成2通过分别用2-氨基苯甲酰胺和1,2-苯二胺对醛进行氧化环化反应,制得-芳基喹唑啉-4(3 H)-ones和2-芳基-1 H-苯并[ d ]咪唑。而且,MNPs-DABCO三溴化物通过在室温下改变溶剂介质,催化了多种醇和酚的三甲基甲硅烷基化/四氢吡喃基化和甲硅烷基化/脱吡喃基化。
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。
Direct AlCl<sub>3</sub>-catalyzed transformation of benzyl THP ethers and allyl benzyl ethers
作者:Tien Tan Bui、Hee-Kwon Kim
DOI:10.1080/00397911.2020.1829644
日期:2021.2.1
THP and allyl groups are frequently used for the protection of alcohols. In this study, novel direct transformations of benzyl THP ethers and allyl benzyl ethers, protected forms of alcohols, are r...
1,1-Disulfo-[2,2-bipyridine]-1,1-hydrogen sulfate, BiPy(SO3H)(2)(HSO4)(2), is prepared and identified as a new ionic liquid. This reagent was used for the promotion of the chemoselective trimethylsilyl and tetrahydropyranyl protection of alcohols. All reactions were performed under mild reaction conditions in high to excellent yields. Ease of the preparation of the heterogeneous catalyst, simplicity and easy work-up procedure, high reaction rates, and recyclability and reusability of the catalyst are the main advantages of this method.