Reaction of alcohols with dihydropyran in the presence of a catalytic amount of Sc(OTf)3 provides efficiently the corresponding tetrahydropyranyl ethers. After the reaction, the catalyst can be recovered quantitatively from the aqueous media and reused without loss of the activity.
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。
Selective tetrahydropyranylation of alcohols and phenols using titanium(IV) salophen trifluoromethanesulfonate as an efficient catalyst
作者:Maryam Yadegari、Majid Moghadam
DOI:10.1002/aoc.3515
日期:2016.10
Titanium(IV) salophen trifluoromethanesulfonate, [TiIV(salophen)(OSO2CF3)2], as a catalyst enables selective tetrahydropyranylation of alcohols and phenols with 3,4‐dihydro‐2H‐pyran. Using this catalytic system, primary, secondary and tertiary alcohols, as well as phenols, were converted to their corresponding tetrahydropyranyl ethers in high yields and short reaction times at room temperature. Investigation
Regioselective Iridium-Catalyzed Asymmetric Monohydrogenation of 1,4-Dienes
作者:Jianguo Liu、Suppachai Krajangsri、Thishana Singh、Giulia De Seriis、Napasawan Chumnanvej、Haibo Wu、Pher G. Andersson
DOI:10.1021/jacs.7b06829
日期:2017.10.18
A highly efficient regio- and enantioselective monohydrogenation of 1,4-dienes has been realized using an iridium catalyst with a chiral N,P-ligand under mild conditions. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the meta- or para-position. Substrates having substituents with functionalities such as silyl protected alcohols or ketals