作者:Douglas C. Behenna、Justin T. Mohr、Nathaniel H. Sherden、Smaranda C. Marinescu、Andrew M. Harned、Kousuke Tani、Masaki Seto、Sandy Ma、Zoltán Novák、Michael R. Krout、Ryan M. McFadden、Jennifer L. Roizen、John A. Enquist、David E. White、Samantha R. Levine、Krastina V. Petrova、Akihiko Iwashita、Scott C. Virgil、Brian M. Stoltz
DOI:10.1002/chem.201003383
日期:2011.12.9
functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reactionscope, and applications in target‐directed synthesis are reported. Experimental observations suggest that these alkylationreactions occur through an unusual inner‐sphere mechanism involving binding of the prochiral
New Applications of 1,5-Hydrogen Atom Transfer Reactions: Self-Oxidizing Protecting Groups
作者:Dennis P. Curran、Hosung Yu
DOI:10.1055/s-1992-34173
日期:——
Three new alcohol protecting groups are introduced: o-bromobenzyl, o-bromo(methylenedioxy)benzyl, and o-bromotrityl. Removal of these protecting groups under reductive conditions with tributyltin hydride is coupled with an oxidation of the substrate to produce directly an aldehyde or ketone. This oxidation occurs by 1,5-hydrogen transfer, followed by ß-fragmentation. For example, treatment of the o-bromobenzyl ether of 3-phenyl-1-propanol with tibutyltin hydride at 0.001 M (80°C) directly produces 3-phenyl-1-propanal. An application to the selective oxidation of primary alcohols in the presence of secondary alcohols is also introduced.
We have developed an efficient method for the preparation of enol silyl ethers using novel agents, silazanes together with NaH or DBU catalyst, wherein TMS and TBDMS groups were smoothly and chemoselectively introduced into ketones and aldehydes under mild conditions.
CuBr-Catalyzed Reaction of<i>N</i>,<i>N</i>-Dimethylanilines and Silyl Enol Ethers: An Alternative Route to β-Arylamino Ketones
作者:Lehao Huang、Xunbin Zhang、Yuhong Zhang
DOI:10.1021/ol901347t
日期:2009.8.20
A wide range of silylenolethers undergo the reactions with N,N-dimethylanilines in the presence of transition metal catalysts under mild conditions to give β-arylamino ketones. In the cases of silylenolethers derived from unsymmetrical ketones, regiospecific addition of carbonyl compounds was obtained at the olefinic position of silylenolether.
Iron(III) Chloride as a Water-Compatible Lewis Acid for Diastereoselective Aldol Reactions in Water in the Presence of a Surfactant
作者:Naohiro Aoyama、Kei Manabe、Shu Kobayashi
DOI:10.1246/cl.2004.312
日期:2004.3
Diastereoselective aldol reactions of various aldehydes with silicon enolates in water have been successfully carried out using iron(III) chloride and a surfactant. Contrary to previous understandi...