Diaminoarylnickel(II) “Pincer” Complexes: Mechanistic Considerations in the Kharasch Addition Reaction, Controlled Polymerization, and Dendrimeric Transition Metal Catalysts

TLDR: The use of the Kharasch addition is often overlooked in synthetic organic chemistry although it has been employed in a number of specific syntheses as mentioned in this paper, and both inter-and intramolecular Kharaussch addition8 is possible.

Abstract: It was in 1945 that researchers at the University of Chicago first reported that carbon tetrachloride could be added directly to olefinic double bonds (eq 1). This process was catalyzed by peroxides as radical initiators.1 This simple reaction is a classic example of anti-Markovnikov addition and has become known as the Kharasch addition reaction,2 in honor of its discoverer, M. S. Kharasch. In the late 1930s, Kharasch and independently Hey and Waters3 had presented a free-radical mechanism to explain this kind of addition reaction, and it is now generally accepted to occur in this manner.4 The use of the Kharasch addition is, however, often overlooked in synthetic organic chemistry although it has been employed in a number of specific syntheses. A few examples of these are shown in eqs 2-6.5-7 Both interand intramolecular Kharasch addition8 is possible.