Halogens addition reactions with

Alkynes undergo addition reactions with halogens. The reaction has been thoroughly examined from a mechanistic point of view. In the presence of excess halogen, tetrahaloalkanes are formed, but mechanistic studies can be carried out with a limited... 

HC1, HBr, and HI add to alkenes by a two-step electrophilic addition mechanism. Initial reaction of the nucleophilic double bond with H+ gives a carbo-cation intermediate, which then reacts with halide ion. Bromine and chlorine add to alkenes via three-membered-ring bromonium ion or chloronium ion intermediates to give addition products having anti stereochemistry. If water is present during the halogen addition reaction, a halohydrin is formed. 

The iron slurries show exceptional reactivity toward oxidative addition reactions with carbon halogen bonds. In fact, the reaction with C.FcI is so exothermic that the slurry has to be cooled to 0 °C before the addition of C F L The reaction of iron with C F Br is also quite exothermic, hence, even for this addition, the iron slurry is cooled to about 0 ° C. The organoiron compound formed in the above reactions, solvated Fe(C.F )2, reacts with CO at room temperature and ambient pressure to yiela Fe(C,F3)2(CO)2(DMEL. 

Alkenes undergo addition reactions with hydrogen to form alkanes, with halogens to form dihaloalkanes, with hydrogen halides to form monohaloalkanes and with water to form alcohols. For example ... 

If. instead of CC14. water is used as the solvent in a halogen addition reaction, a halohydrin is formed. The student proposed that such a reaction would follow Mechanism A with water replacing bromine as the nucleophile. If this hypothesis is correct, which of the following is the most likely product for the addition of bromine to propene in water ... 

Alkenes are similar to alkanes in structure and also undergo combustion. However, they are much more likely to undergo addition reactions with halogens, rather than substitution. Addition reactions occur with a wide variety of reagents. 

S. Torii, T. Inokuchi, Addition Reactions with Formation of Carbon-Halogen Bonds, in Comprehensive Organic Synthesis (B. M. Trost, I. Fleming, Eds.), Vol. 7, 527, Pergamon Press, Oxford, 1991. 

The di-iodides (81), formed from cyclopropenes by addition of iodine with rearrangement also eliminate halogen on reaction with methyllithium, providing a simple route to l-vinyl-2-alkylbicyclo[l. 1. OJbutanes180. 

Addition reactions occur by breaking the n bonds of the triple bond. Hydrogen, halogens, hydrogen halides and water may give addition reactions with alkynes. 

Alkynes undergo addition reactions with halogens (CI2, Br2) to produce tetrahalo alkanes. To saturate each allqme molecule, two halogen molecules are needed. Alkynes decolorize aqueous Br2 solution, as alkenes do. 

It undergoes addition reactions with hydrogen, halogens, hydrogen halides and water. 

Addition Reactions with Formation of Carbon-Halogen Bonds... 

Addition Reactions with Formation of Carbon-Halogen Bonds Table 1 Halogenation of Enol Ethers and Esters with Metallic Reagents... 

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