Intramolecular Friedel–Crafts Acylation Reaction Promoted by 1,1,1,3,3,3-Hexafluoro-2-propanol
作者:Hashim F. Motiwala、Rakesh H. Vekariya、Jeffrey Aubé
DOI:10.1021/acs.orglett.5b02851
日期:2015.11.6
Simple dissolution of an arylalkyl acid chloride in 1,1,1,3,3,3-hexafluoro-2-propanol promotes an intramolecularFriedel–Craftsacylation without additional catalysts or reagents. This reaction is operationally trivial in both execution and product isolation (only requiring concentration followed by purification) and accommodates a broad range of substrates. Preliminary studies that bear upon potential
Aminothiocarbamate-Catalyzed Asymmetric Bromolactonization of 1,2-Disubstituted Olefinic Acids
作者:Chong Kiat Tan、Ling Zhou、Ying-Yeung Yeung
DOI:10.1021/ol200840e
日期:2011.5.20
An efficient and enantioselectivebromolactonization of 1,2-disubstituted olefinicacids using an amino-thiocarbamate catalyst has been developed, resulting in the formation of δ-lactones containing two chiral centers with up to 99% yield, 95% ee.
Compounds of formula (I):
wherein:
A, R, T, Q, L, Z, G, X and A' are as defined in the description.
B and D, equal to or different from each other, are selected between heteroaryl and aryl, wherein at least one of the hydrogen atoms of said heteroaryl and aryl are substituted with groups selected from SO3-, SO3H, COO-, COOH, and one or more of the other hydrogen atoms of said heteroaryl and aryl are optionally substituted as reported in the description.
A highly enantioselective approach towards 2-substituted 3-bromopyrrolidines
作者:Jie Chen、Ling Zhou、Ying-Yeung Yeung
DOI:10.1039/c2ob25327e
日期:——
A facile and highly enantioselective approach towards 2-substituted 3-bromopyrrolidines has been developed. The process involves an amino-thiocarbamate catalyzed bromoaminocyclization of 1,2-disubstituted olefinic amides. The pyrrolidine products could readily be converted into other useful building blocks including a dihydropyrrole and a 2-substituted pyrrolidine.
A catalytic enantioselective bromocyclization of olefinic amides using amino-thiocarbamates as the catalysts has been developed. The resulting enantioenriched 2-substituted 3-bromopiperidines can readily be transformed to 3-substituted piperidines through a silver salt-mediated rearrangement. This process has been applied to the synthesis of a dopaminergic drug, Preclamol.