Part 148 in the Series “Studies on Novel Synthetic Methodologies:” Selective Acetylation of Alcohols, Phenols and Amines and Selective Deprotection of Aromatic Acetates using Silica-Supported Phosphomolybdic Acid
efficient catalyst for the selective acetylation of alcohols, phenols and amines in the absence of any solvent and also for the chemoselective deprotection of aromatic acetates under very mild conditions. This method has been used for the protection of the hydroxy groups as well as for the deprotection of the acetates of several naturally occurring bioactive phenolic compounds. The catalyst can be easily
A series of air-stable chiralferrocenylphosphines (LB1–LB4) were prepared and used in the asymmetric allylicsubstitution of Morita–Baylis–Hillman (MBH) adducts with phthalimide under mild reaction conditions; the (R,SFc)-ferrocenylphosphine LB4 afforded the desired amination products 3 in moderate yields with excellent enantioselectivities. The absolute configuration of 3o was confirmed by X-ray
Ligand-Dependent Regiodivergent Enantioselective Allylic Alkylations of α-Trifluoromethylated Ketones
作者:Yi Zhu、Yifan Ni、Chenxi Lu、Xiaochen Wang、Yi Wang、Xiao-Song Xue、Yi Pan
DOI:10.1021/acs.orglett.1c00329
日期:2021.4.2
catalytic and enantioselective addition of α-CF3 enolates allows for expeditious access to functionalized chiral building blocks with CF3-containing stereogenicity. The computational studies reveal that the choice of ligand in a designed palladium-complex system regulates the regioselectivity and stereoselectivity of the asymmetric allylic alkyation of α-CF3 ketones and Morita–Baylis–Hillmanadducts.
Enantioselective allylic substitution of Morita–Baylis–Hillman adducts catalyzed by planar chiral [2.2]paracyclophane monophosphines
作者:Tang-Zhi Zhang、Li-Xin Dai、Xue-Long Hou
DOI:10.1016/j.tetasy.2007.08.005
日期:2007.8
Planar chiral [2,2]cyclophane monophosphines are efficient catalyst in the reaction of Morita–Baylis–Hillmanadducts with phthalimide. The corresponding allylicsubstituted products were afforded in high yields and in good to moderate ee.
A silver/palladium relay catalyzed 1,3-dipole annulation/allylation reaction of iminoesters and Baylis-Hillman acetates for the construction of fully substituted allyl imidazolidines is reported. The reaction of both iminoesters and Baylis-Hillman acetates affords the fully substituted allyl imidazolidines in high yields and regioselectivities. The three component reaction is triggered by silver-catalyzed