Copper-catalyzed carbonylative reaction

The potential of aminosulfoximines 85 to be used as ligands in copper-catalyzed carbonyl-ene reactions was also examined [73, 74]. Interestingly, in this case, unsymmetrically substituted 95 gave the best results (up to 91% ee for the synthesis of 94 with R = Me Scheme 2.1.1.32) [75]. 

The synthesis of succinic acid derivatives, /3-alkoxy esters, and a,j3-unsaturated esters from olefins by palladium catalyzed carbonylation reactions in alcohol have been reported (24, 25, 26, 27), but full experimental details of the syntheses are incomplete and in most cases the yields of yS-alkoxy ester and diester products are low. A similar reaction employing stoichiometric amounts of palladium (II) has also been reported (28). In order to explore the scope of this reaction for the syntheses of yS-alkoxy esters and succinic acid derivatives, representative cyclic and acyclic olefins were carbonylated under these same conditions (Table I). The reactions were carried out in methanol at room temperature using catalytic amounts of palladium (II) chloride and stoichiometric amounts of copper (II) chloride under 2 atm of carbon monoxide. The methoxypalladation reaction of 1-pentene affords a good conversion (55% ) of olefin to methyl 3-methoxyhexanoate, the product of Markov-nikov addition. In the carbonylation of other 1-olefins, f3-methoxy methyl esters were obtained in high yields however, substitution of a methyl group on the double bond reduced the yield of ester markedly. For example, the carbonylation of 2-methyl-l-butene afforded < 10% yield of methyl 3-methyl-3-methoxypentanoate. This suggests that unsubstituted 1-olefins may be preferentially carbonylated in the presence of substituted 1-olefins or internal olefins. The reactivities of the olefins fall in the order RCH =CHo ]> ci -RCH=CHR > trans-RCH =CHR >... 

Indanes, chromium tricarbonyl complexes, 5, 246 Indazoles, in copper-catalyzed lead reactions, 9, 409 Indenes, chromium tricarbonyl complexes, 5, 246 Indenide derivatives, alkali compounds, 2, 13 Indenones, via imine carbonylation, 10, 136 Indenyl-alkoxo complexes, with Ti(IV), 4, 500 Indenyl-amido complexes, with Ti(IV), 4, 454 Indenyl-amido dimethyl complexes, with Ti(IV), 4, 442 Indenyl bridges, in [Pg.126]

Copper(I) triflate was used as a co-catalyst in a palladium-catalyzed carbonylation reaction (Sch. 27). The copper Lewis acid was required for the transformation of homoallylic alcohol 118 to lactone 119. It was suggested that the CuOTf removes chloride from the organopalladium intermediate to effect olefin complexation and subsequent migratory insertion [60]. Copper(I) and copper(II) chlorides activate ruthenium alkylidene complexes for olefin metathesis by facilitating decomplexation of phosphines from the transition metal [61]. 

Satoh T, Kokubo K, Miura M et al (1994) Effect of copper and iron cocatalysts on the palladium-catalyzed carbonylation reaction of iodobenzene. Organometallics 13 4431 1436... 

Conjugate addition to an a,3-unsaturated carbonyl compound is achieved routinely by using a lithium organocopper reagent or a copper-catalyzed Grignard reaction. " It should be noted that in many of these examples, and in particular in the case of lithium diorganocuprates, the resultant enolate has... 

Transition-metal-catalyzed carbonylation reactions have shown impressive progress during past few decades especially, the use of ruthenium, rhodium, and palladium as catalysts is widespread. More recently, iron and copper catalysts have also been attracting the attention of synthetic chemists because of their low cost and environmentally benign properties. 

In 2008, Bhanage and coworkers [50a] reported on a copper-catalyzed carbonylative Sonogashira reaction of aryl iodides. In this procedure, copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) [Cu(TMHD)2 was used as the catalyst for this transformation and NEtj as base. Alkynones were produced in good yields. Recently, Xia and coworkers [50b] described a general and efficient copper-catalyzed... 

Scheme 5.33 Copper-catalyzed carbonylative Sonogashira reaction...

The enantioselective 1,4-addition addition of organometaUic reagents to a,p-unsaturated carbonyl compounds, the so-called Michael reaction, provides a powerful method for the synthesis of optically active compounds by carbon-carbon bond formation [129]. Therefore, symmetrical and unsymmetrical MiniPHOS phosphines were used for in situ preparation of copper-catalysts, and employed in an optimization study on Cu(I)-catalyzed Michael reactions of di-ethylzinc to a, -unsaturated ketones (Scheme 31) [29,30]. In most cases, complete conversion and good enantioselectivity were obtained and no 1,2-addition product was detected, showing complete regioselectivity. Of interest, the enantioselectivity observed using Cu(I) directly in place of Cu(II) allowed enhanced enantioselectivity, implying that the chiral environment of the Cu(I) complex produced by in situ reduction of Cu(II) may be less selective than the one with preformed Cu(I). 

No specific recommendations can be given about the optimum reaction time. As speeding up reactions is a key motive for employing microwave irradiation, the reaction should be expected to reach completion within a few minutes. On the other hand, a reaction should be run until full conversion of the substrates is achieved. In general, if a microwave reaction under sealed-vessel conditions is not completed within 60 min then it needs further reviewing of the reaction conditions (solvent, catalyst, molar ratios). The reported record for the longest microwave-mediated reaction is 22 h for a copper-catalyzed N-arylation (see Scheme 6.63). The shortest ever published microwave reaction requires a microwave pulse of 6 s to reach completion (ultra-fast carbonylation chemistry see Scheme 6.49). 

A copper-catalyzed reaction using a chiral diphosphine hgand, DuPHOS, with an added lanthanide salt, provides good levels of enantioselectivity (67-91% ee) in additions of the simple allylboronate 31 to both aromatic and aliphatic ketones that present a large difference of steric bulk on the two sides of the carbonyl group. One such example is shown in Eq. 81. On the basis of B NMR experiments and on the lack of diastereoselectivity in crotylation reactions, the... 

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