Electrophilic reactions natural product synthesis

It is the hope of the authors that the compilation of the results gained hitherto in the field of electrophilic cyclopropanes will stimulate further interest in this area. The numerous reactions described in this survey article are an indication of the potential of the title compounds in organic chemistry. Their utility has already been demonstrated in various domains, including natural product synthesis, selective transformations, ring expansions, etc. However, only the basic chemistry of the electrophilic cyclopropanes has been unraveled and results originating from the application of new and modern selective reagents will certainly broaden the scope of its possibilities. 

The tether directing strategies for C- and O-glycosylation are one subset of a much wider area of using the temporary connection for controlling the regio- and stereochemical outcome in the reaction of nucleophiles with an electrophilic substrate. Some examples of this form of tether-mediated S3mthesis will be illustrated with some applications to natural product synthesis [109]. 

Olefin metathesis reaction that reorganizes carbon-carbon double bonds provides fundamentally new strategies for natural product synthesis and polymer chemistry. Hilvert and coworkers built up an artificial metalloenzyme by covalently tethering a Grubbs-Hoveyda-type Ru complex to a protein scaffold [78]. An /V-heterocyclic carbene (NHC) ligand, which has been reported as a suitable ligand for a number of water-soluble ruthenium-based metathesis catalysts, was derivatized with an electrophilic bromoacetamide. The Ru carbene complex (27 in Figure 10.16) was then attached by site-selective alkylation of the cysteine... 

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