The 2-(2-Azidoethyl)cycloalkanone Strategy for Bridged Amides and Medium-Sized Cyclic Amine Derivatives in the Aubé-Schmidt Reaction
作者:John Murphy、Fraser Macleod、Stuart Lang
DOI:10.1055/s-0029-1219340
日期:2010.3
2-(2-Azidoethyl)cycloalkanones afford bridged lactams in the Aube-Schmidt reaction, sometimes in excellent yield, and solvolysis yields derivatives of medium-ring amines. Attempts to divert the Schmidt reaction with an arene-mediated fragmentation of the normal Schmidt intermediate have led to an initial example.
Reported herein is a visible‐light‐mediated radical approach to the α‐alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2‐based activation of alkyl halides and blue light irradiation. The resulting open‐shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl
Ruthenium-Catalyzed Hydrative Cyclization of 1,5-Enynes
作者:Yiyun Chen、Douglas M. Ho、Chulbom Lee
DOI:10.1021/ja053462r
日期:2005.9.1
ruthenium-catalyzed hydrative cyclization of enynes has been developed. The reaction converts a range of 1,5-enynes bearing terminal alkyne and Michael acceptor moieties into cyclopentanone derivatives. From extensive catalyst screening experiments, a trinuclear ruthenium complex, [Ru3(dppm)3Cl5]PF6, has been identified to be an effective catalyst in mediating the 1,1-difunctionalization of alkynes. It is proposed
Investigation of Straightforward, Photoinduced Alkylations of Electron‐Rich Heterocompounds with Electron‐Deficient Alkyl Bromides in the Sole Presence of 2,6‐Lutidine
photosensitizer: We introduce a method for selective photoinduced alkylations of electron‐rich heterocompounds with electron‐deficient allylbromides in the presence of 2,6‐lutidine at 365 or 405 nm. Mechanistic investigations reveal that a colored intermediate formed from 2,6‐lutidine and alkyl bromide is involved in the photoactivation. Our approach uses commercially available reagents and a straightforward
Reaction Control in Synthetic Organic Photochemistry: Switching between [5+2] and [2+2] Modes of Cycloaddition
作者:Claudio Roscini、Kara L. Cubbage、Malcolm Berry、Andrew J. Orr-Ewing、Kevin I. Booker-Milburn
DOI:10.1002/anie.200904059
日期:2009.11.2
Split personality: Reaction conditions that enable powerful control over the mode of photocycloaddition in maleimides have been developed. Direct irradiation favors the [5+2] mode whereas sensitized irradiation allows a complete switch to the [2+2] mode (see scheme; TBS=tert‐butyldimethylsilyl).