Alkenyl benzyl ethers

Alfrey-Price Q and e-values, 304, 307, 309, 310, 314, 334, 337, 342, 352, 353, 389, 393-395, 400, 416, 419, 424 MA monomer, 247, 272 Alkali cyanide, addition to fumarates, 64 Alkenyl benzyl ethers, MA copolymerization, 532 Alkenylsuccinic anhydride applications, 147, 175 double bond migration, 174 hydrolysis, 175 isomerization catalysts, 174 MA polymerization, 342 MA-olefin adducts, 147-151, 163-165, 172, 173 Alkoxysuccinic acids, preparation, 46 Alkyd resins, MA applications, 44, 479, 499 Alkyl acetoacetates... 

Gyclization/hydrosilylation of enynes catalyzed by rhodium carbonyl complexes tolerated a number of functional groups, including acetate esters, benzyl ethers, acetals, tosylamides, and allyl- and benzylamines (Table 3, entries 6-14). The reaction of diallyl-2-propynylamine is noteworthy as this transformation displayed high selectivity for cyclization of the enyne moiety rather than the diene moiety (Table 3, entry 9). Rhodium-catalyzed enyne cyclization/hydrosilylation tolerated substitution at the alkyne carbon (Table 3, entry 5) and, in some cases, at both the allylic and terminal alkenyl carbon atoms (Equation (7)). 

It was previously observed that with a catalytic amount of FeCls, benzylic alcohols were rapidly converted to dimeric ethers by eliminating water (Scheme 14). In the presence of an alkyne this ether is polarized by FeCls and generates an incipient benzylic carbocation. The nucleophilic attack of the alkyne moiety onto the resulting benzyl carbocation generated a stable alkenyl cation, which suffer the nucleophilic attack of water (generated in the process and/or from the hydrated... 

Nickel-bpy and nickel-pyridine catalytic systems have been applied to numerous electroreductive reactions,202 such as synthesis of ketones by heterocoupling of acyl and benzyl halides,210,213 addition of aryl bromides to activated alkenes,212,214 synthesis of conjugated dienes, unsaturated esters, ketones, and nitriles by homo- and cross-coupling involving alkenyl halides,215 reductive polymerization of aromatic and heteroaromatic dibromides,216-221 or cleavage of the C-0 bond in allyl ethers.222... 

R = alkyl, alkenyl, alkynyl, aryl, acetate, ester, benzyl or silyl ether groups Scheme 6.15 Cleavage of methoxyphenyl methyl (MPM) ethers using clayan. 

Palladium-catalyzed asymmetric cyclization/hydrosilylation tolerated a number of functional groups including benzyl and pivaloyl ethers as well as benzyl and methyl esters (Table 8, entries 1-4). Furthermore, the protocol tolerated substitution at one of the two /ra/zi -terminal alkenyl positions and at one of the two allylic positions of the 1,6-diene (Table 8). As was the case with diene cyclization/hydrosilylation catalyzed by achiral palladium... 

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