Search results for "Electrophilic addition"
showing 6 items of 6 documents
A new electrophilic addition to acetylenes. Synthesis of 1,2-iodofunctionalized olefins
1986
Abstract Acetylenes react with bis(pyridine)iodo(I) tetrafluoroborate ( 1 ) in the presence of a wide variety of nucleophiles (F, Cl, Br, I, SCN, pyridine, OAc, anisole, H) to give 1,2-iodofunctionalized olefins ( 4 ).
Chapter 9 The electrophilicity index in organic chemistry
2007
Abstract We review in this chapter the applications of theoretical scales of global and local electrophilicity to rationalize the reactivity and selectivity for a significant number of reactions in organic chemistry. The model is based on the global electrophilicity index, formerly introduced by Maynard et al. and further formalized by Parr et al. The global electrophilicity index categorizes, within a unique absolute scale, the propensity of electron acceptors to acquire additional electronic charge from the environment. The local extension of this index provides useful information about the active sites of electrophiles, thereby allowing the characterization of the intramolecular selectiv…
cis-bromination of alkynes without cationic intermediates
2005
The nature of the chemical bond in (CH3)3N-BCl3 and (CH3)3N-AlCl3
1994
Michael additions to double bonds of esters of N-protected (s)-phenylalanyldehydroalanine (X-(s)-Phe-ΔAla-OMe) and its phosphonic acid counterpart (X…
2017
Electrophilic addition of amines, thiols and bromide to the double bonds of model dehydrodipeptides and dehydrophosphonodipeptide was studied. The double bond in these two classes of peptides reacted similarly and gave the same products. These results indicate that dehydropeptides are very good candidates as substrates for modifications of peptide side-chains.
Why do Electron-Deficient Dienes React Rapidly in Diels?Alder Reactions with Electron-Deficient Ethylenes? A Density Functional Theory Analysis
2004
The Diels−Alder reaction of the electron-deficient (ED) dimethyl 2,3-dimethylenesuccinate with two electron-rich (ER) and two ED ethylenes has been studied at the B3LYP/6-31G* level of theory. The analysis of the geometry and electronic structure of the transition state of the reaction with the ED dimethyl 2-methylenemalonate along with the analysis of the global and local electrophilicity indices of the reagents provide an explanation of the participation of this ED diene as nucleophile against powerful electrophiles in polar Diels−Alder reactions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)