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Organozincs, amination

Because of their ease of crystallization, alkylzinc alkoxides are often isolated as decomposition products in reactions involving organozinc compounds. The methylzinc lithium tert- butoxide heterocubes [ (THF)LiOBut 2-(MeZnOBu1 ]182 (Figure 58, 123) and [(LiOBu MeZnOBu1 ]183 124 were isolated as hydrolysis products from reactions involving amines, amidines, /< //-butyllithium, and dimethylzinc. [Pg.366]

Benzotriazole-containing resin 167 reacted with aldehydes and amines to give resin-bound Mannich adducts 168, which reacted with Grignard and organozinc reagents to afford tertiary amines 169 <00JCC173>. [Pg.181]

The benzotriazole derivatives 111, obtained from benzotriazole, ethyl glyoxylate and secondary amines (diethylamine, pyrrolidine, piperidine or morpholine), furnish the amino esters 112 by the action of organozinc reagents R2ZnX (R2 = Me, Bu, PhCH2 or Ph)120. [Pg.556]

A-Mono- and iV,iV-disubstituted 0-benzoylhydroxylamines 2a-i recently developed for amination of organozinc and Grignard reagents and 0-acylhydroxylamines 2j-l for amination of enolates have been listed in Table 2. 0-Benzoylhydroxylamines were prepared by Berman and Johnson " by oxidation of primary and secondary amines with... [Pg.311]

It has been known for a long time that organozinc amides derived from secondary or primary amines usually exist as dimers in solution . However, depending on the particular groups bound to zinc and/or nitrogen, examples of higher aggregates are also known. [Pg.111]

One of the first reports dealing with the carbozincation of alkenes by allylic organozinc reagents was the addition of allylzinc bromide to the homoallylic amine 118 which occurred in refluxing THF. A secondary organozinc 119 was regioselectively produced and provided the amine 120 after hydrolysis. A small amount of aminoalcohol 121, resulting from oxidation of 119, was also isolated when the reaction mixture was exposed to air (equation 52)80,81. [Pg.891]

As a general rule, allylic organozinc reagents do not react with unactivated a, ji-disubstituted alkynes. A few exceptions to this trend have been observed in the case of substrates bearing an appropriately located heteroatom such as the homopropargylic tertiary amine 147. The latter reacted regioselectively with allylzinc bromide but led to a 67/33 mixture of two geometric isomers, apparently derived from syn and anti additions (equation 71)82,105. [Pg.899]

Nevertheless, chiral propargylic amines remain interesting substrates for achieving the diastereoselective addition of substituted allylic organozinc compounds to metallated alkynes. Besides crotylzincation, one example of diastereoselective addition of zincated allyl ethyl ether to 328 has also been reported183. [Pg.945]

Organometallic compounds asymmetric catalysis, 11, 255 chiral auxiliaries, 266 enantioselectivity, 255 see also specific compounds Organozinc chemistry, 260 amino alcohols, 261, 355 chirality amplification, 273 efficiency origins, 273 ligand acceleration, 260 molecular structures, 276 reaction mechanism, 269 transition state models, 264 turnover-limiting step, 271 Orthohydroxylation, naphthol, 230 Osmium, olefin dihydroxylation, 150 Oxametallacycle intermediates, 150, 152 Oxazaborolidines, 134 Oxazoline, 356 Oxidation amines, 155 olefins, 137, 150 reduction, 5 sulfides, 155 Oxidative addition, 5 amine isomerization, 111 hydrogen molecule, 16 Oxidative dimerization, chiral phenols, 287 Oximes, borane reduction, 135 Oxindole alkylation, 338 Oxiranes, enantioselective synthesis, 137, 289, 326, 333, 349, 361 Oxonium polymerization, 332 Oxo process, 162 Oxovanadium complexes, 220 Oxygenation, C—H bonds, 149... [Pg.196]

Keywords Catalyst, Alkylation, Allylation, Arylation, Mannich reaction, Carbon-nitrogen double bond, Imine, Nitrone, Aldimine, Organozinc reagents, Silyl ketene acetal, Silyl enol ether, Amine, (3-Amino acid... [Pg.107]

Recently, three research groups independently disclosed that benzotriazoles 18 attached through various linkers to a polymeric support react with aldehydes and amines to form polymer-anchored Mannich-type adducts 19 (Scheme 7) [29]. These intermediates are cleaved under reducing conditions and in the presence of organomagnesium or organozinc reagents to provide libraries of secondary and tertiary amines in moderate yield (11-65%) and with acceptable purity (13->99%) [29]. [Pg.269]

XXXV) and (XXXVI) indicates the occurrence of heterolytic cleavage of the C-3-C-4 bond of the amine (XXXIV). In the presence of an excess of allylzinc bromide, only the amines (XXXIV) and (XXXVI) are isolated. Similar types of reactions have been observed in the reactions of allylic organozinc reagents with unsaturated alcohols (333). The reaction of allylzinc bromide with the branched alcohol (XXXVII) forms both the allylcarbinol (XXXVIII) and the rearranged linear alcohol (XXXIX) (333). [Pg.107]

Allylic organozinc compounds react with amino ether and aminothio ether to give unsaturated amines in good yields (96, 329). For example,... [Pg.115]


See other pages where Organozincs, amination is mentioned: [Pg.12]    [Pg.307]    [Pg.351]    [Pg.395]    [Pg.67]    [Pg.77]    [Pg.5]    [Pg.559]    [Pg.280]    [Pg.110]    [Pg.416]    [Pg.280]    [Pg.308]    [Pg.312]    [Pg.314]    [Pg.334]    [Pg.334]    [Pg.894]    [Pg.943]    [Pg.956]    [Pg.230]    [Pg.280]    [Pg.737]    [Pg.418]    [Pg.326]    [Pg.348]    [Pg.279]    [Pg.126]    [Pg.544]    [Pg.544]    [Pg.186]    [Pg.184]    [Pg.280]    [Pg.110]    [Pg.117]    [Pg.4763]   
See also in sourсe #XX -- [ Pg.308 , Pg.312 , Pg.313 , Pg.334 ]




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