Allyl replacement

Allyl replacement. The radical reaction is suitable for preparation of homo-illylic fluoro compounds from gew-nitroalkyl fluorides. 

A white solid, m.p. 178 C. Primarily of interest as a brominaling agent which will replace activated hydrogen atoms in benzylic or allylic positions, and also those on a carbon atom a to a carbonyl group. Activating influences can produce nuclear substitution in a benzene ring and certain heterocyclic compounds also used in the oxidation of secondary alcohols to ketones. 

Allyl cyanide. Into a 1 5 litre three-necked flask (1), provided with a mercury-sealed stirrer and two long double surface condensers, place 293 g. (210 ml.) of freshly-distilled allyl bromide, b.p. 70-71° (Section III, 35) and 226 g. of dry cuprous cyanide (Section 11,50,3, Method 1), Remove the mercury-sealed stirrer and replace it by a tightly fitting... 

Catalytic hydrogenation is mostly used to convert C—C triple bonds into C C double bonds and alkenes into alkanes or to replace allylic or benzylic hetero atoms by hydrogen (H. Kropf, 1980). Simple theory postulates cis- or syn-addition of hydrogen to the C—C triple or double bond with heterogeneous (R. L. Augustine, 1965, 1968, 1976 P. N. Rylander, 1979) and homogeneous (A. J. Birch, 1976) catalysts. Sulfur functions can be removed with reducing metals, e. g. with Raney nickel (G. R. Pettit, 1962 A). Heteroaromatic systems may be reduced with the aid of ruthenium on carbon. 

Replacement of the proton on nitrogen in succinimide by bromine gives N bromo succinimide a reagent used for allylic and benzylic brominations (Sections 10 4 and 1112)... 

Because of processing problems 2-chloroethyl vinyl ether has now been replaced with other cure site monomers. These include vinyl and allyl chloracetates and allyl glycidyl ether. 

Reactions of ar>l or alkyl bis(siloxy)isopropyl ethers with tetrabutyl-ammoninm fluoride-mesyl fluoride reagent lead to replacement of one siloxy group by fluorine and dehydrosiloxylation, providing an efficient access to fluoroisopropenyl ethers, which are useful as specific building blocks in drug design The reactions proceed via the intermediate allyl methanesulfonates [30, 31] (equation 23)... 

Vinyl and phenyl mfluoromethyl groups are reactive in the presence of aluminum chloride [10] Replacement of fluorine by chlorine often occurs Polyfluori-nated trifluoromethylbenzenes form reactive a,a-difluorobenzyl cations in antimony pentafluoride [11] 1 Phenylperfluoropropene cyclizes in aluminum chloride to afford 1,1,3-trichloro 2 fluoroindene [10] (equation 10) The reaction IS hypothesized to proceed via an allylic carbocation, whose fluoride atoms undergo halogen exchange... 

The 3,5-bis(trifluoromethyl)pyrazolate analog [Ir(cod)(/x-3,5-(CF3)2pz)]2 does not enter into oxidative addition with iodine, methyl iodide, or acetylenes. The mixture of pyrazolate and 3,5-bis(trifluoromethyl)pyrazolate gives [(rj -codllrf/x-pz)(/L-3,5-(CF3)2pz)Ir(rj -cod)], which reacts with bis(trifluoromethyl)acetylene in a peculiar manner [83JCS(CC)580], producing 145, where 3,5-bis(trifluoromethyl) pyrazolate is replaced by the ethylene bridge and the rj -coordination mode of one of the cod ligands is converted into the rj -allylic mode. 

The prototype of this series is synthesized by first reacting morphine with cyanogen bromide. This reagent in effect serves to replace the methyl group by cyano. Hydrolysis of the intermediate (11) affords desmethylmorphine (12). Alkylation of the last with allyl bromide affords nalorphine (13). ... 

It has been found empirically that central analgesics that possess some degree of activity as antagonists of the effects of morphine tend to show a reduced propensity for causing physical addiction. Again empirically, it was noted that this could often be achieved by replacement of the N-methyl group by allyl, cyclopropylmethyl, or cyclobutylmethyl additional nuclear modifications often contributed to this activity. 

Allyl silanes react with transition metals bearing chlorine ligands to give allyl chlorides, where a chlorine replaces a Mc3Si unit. °... 

The COOH group of a P-keto acid is replaced by an allylic group when the acid is... 

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