Allylmagnesium Halides Do Not React Chemoselectively Because Reaction Rates Approach the Diffusion Limit
作者:Jacquelyne A. Read、K. A. Woerpel
DOI:10.1021/acs.joc.7b00053
日期:2017.2.17
that additions of allylmagnesium halides to carbonyl compounds, unlike additions of other organomagnesium reagents, occur at rates approaching the diffusion rate limit. Whereas alkylmagnesium and alkyllithium reagents could differentiate between electronically or sterically different carbonyl compounds, allylmagnesium reagents reacted with most carbonyl compounds at similar rates. Even additions to esters
Generation of allyl Grignard reagents via titanocene-catalyzed activation of allyl halides
作者:Lauren M. Fleury、Brandon L. Ashfeld
DOI:10.1016/j.tetlet.2010.02.144
日期:2010.5
A protocol for the generation of allylGrignardreagents via the catalytic activation of allyl halides is described herein. Subsequent nucleophilic addition to carbonyl derivatives provided the desired homo allylic alcohols in excellent yields (84–99%). Evidence suggests that titanocene dichloride catalyzes the formation of an allylGrignard species which reacts solely with the carbonyl electrophile
Cooperative Titanocene and Phosphine Catalysis: Accelerated C–X Activation for the Generation of Reactive Organometallics
作者:Lauren M. Fleury、Andrew D. Kosal、James T. Masters、Brandon L. Ashfeld
DOI:10.1021/jo301726v
日期:2013.1.18
transmetalation approach toward the generation of Grignard and organozinc reagents mediated by a titanocene catalyst. This method enables the metalation of functionalized substrates without loss of functional group compatibility. Allyl zinc reagents and allyl, vinyl, and alkyl Grignard reagents were generated in situ and used in the addition to carbonyl substrates to provide the corresponding carbinols in yields
A Mild and Efficient Three-Component Synthesis of Secondary and Tertiary Homoallylic Hydrazides
作者:Bum Seok Lee、Doo Ok Jang
DOI:10.1002/ejoc.201201757
日期:2013.5
Zn(ClO4)2·6H2O was developed for the syntheses of secondary and tertiary homoallylic hydrazides. Excellent chemoselectivities and diastereoselectivies were observed. Aldehydes as well as acyclic and cyclic ketones were well-suited to the reaction conditions and provided secondary and tertiary homoallylic hydrazides in excellent yields.
An atom-economic sulfonylation of unsaturated benzylic alcohols in water is described. In this transformation, dual roles of sulfonyl hydrazides serving as both sulfonyl source and reductant have been demonstrated, which enabled a facile and green method to synthesize alkyl sulfones from unsaturated benzylic alcohols. Moreover, this approach provides a practical access to deuterated alkanes from the