Allylic bromides functional group

The oxidation of higher alkenes in organic solvents proceeds under almost neutral conditions, and hence many functional groups such as ester or lac-tone[26,56-59], sulfonate[60], aldehyde[61-63], acetal[60], MOM ether[64], car-bobenzoxy[65], /-allylic alcohol[66], bromide[67,68], tertiary amine[69], and phenylselenide[70] can be tolerated. Partial hydrolysis of THP ether[71] and silyl ethers under certain conditions was reported. Alcohols are oxidized with Pd(II)[72-74] but the oxidation is slower than the oxidation of terminal alkenes and gives no problem when alcohols are used as solvents[75,76]. 

Otera et al. extended the tin-mediated allylation to 2-substituted allyl bromides.80 When 2-bromo and 2-acetoxy-3-bromo-l-propene were used, the allylation with tin produced the corresponding functionalized coupling products (Eqs. 8.36 and 8.37). In the case of 2,3-dibromopropene, the reaction occurred exclusively through allylation in the presence of the vinyl bromo group. The presence of other electrophiles such as a nitrile (-CN) or an ester (-COOR) did not interfere with the reaction. 

Telechelic polymers, containing one or more end groups with the capacity to react with other molecules, are useful for synthesizing block and other copolymers [Fontanille, 1989 Hsieh and Quirk, 1996 Nuyken and Pask, 1989 Pantazis et al., 2003 Patil et al., 1998 Quirk et al., 1989, 1996 Rempp et al., 1988]. Living anionic polymers can be terminated with a variety of electrophilic reagents to yield telechelic polymers. For example, reaction with carbon dioxide, ethylene oxide, and allyl bromide yield polymers terminated with carboxyl, hydroxyl, and allyl groups, respectively. Functionalization with hydroxyl or carboxyl groups can also be achieved by reaction with a lactone or anhydride, respectively. Polymers with amine end... 

Allyl halides are also alkylated by zinc cyanocuprates. Allylic bromides, iodides and chlorides react successfully with these reagents, and a number of functional groups in the allylic halide (ester, sulfide, sulfoxide, ether, alkyl halides, acetals) stand up well to the conditions of reaction (equations 29 and 30)41 3. The regiochemistry of attack is predominantly Sn2. 1,3-Dichloroalkenes can be made to undergo two successive coupling reactions to this point, only two identical R group incorporations have been reported (equation 31)44. 

An example for the use of the boron-zinc exchange reaction for copper-mediated SN2 -substitutions of allylic electrophiles is the hydroboration of nitroolefin 130 with diethylborane, followed by successive transmetallation of the borane 131 with diethylzinc and CuCN-2LiCl, and final trapping with allyl bromide to give the product 133 with 83% yield over four steps (Scheme 34).34,34a This transformation again demonstrates the tolerance of the method towards functional groups and acidic hydrogen atoms. 

Functional group (FG) = Br, CONR2, CN, C02Et, C02tBu E-Y = aldehyde, allyl bromide... 

An additional functional group may be present in one of the reactants. Alkylation of vinylacetylene gives low yields of l-alken- ynes. - Cuprous halide catalyst is required for alkylations by allyl bromide the yields of l-alken-4-ynes are about 88%. Both halogen atoms of dibromides can be induced to take part in alkylation if the halogens are not on the same or adjacent carbon atoms. The yields of diynes are 46-85%. Diynes in... 

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