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Vinyl triflates cross-coupling

Vinylation can also be done by Pd-catalysed cross-coupling in which one component is used as a halide or triflate and the other as a stannane (Stille reaction) or boronic acid (Suzuki reaction). Entry 9, Table 11.3, is an example of the use of a vinylstannane with a haloindole. lndole-3-boronic acids, which can be prepared by mcrcuration/boration, undergo coupling with vinyl triflates (Entry 10). [Pg.111]

The key step in a short and efficient synthesis of pleraplysillin-1 (127) is the palladium-catalyzed cross-coupling of vinylstannane 125 with vinyl triflate 126 (see Scheme 33). This synthesis is noteworthy in two respects. First, vinyl triflate 126 is generated regio-specifically from the kinetic enolate arising from a conjugate reduction of enone 124 the conjugate reduction of an enone is, in fact, a... [Pg.594]

Similarly, nickel catalysis permits the extension of cross coupling to vinyl phosphates, which are in some cases more readily obtained and handled than vinyl triflates.273... [Pg.758]

Most of the work on the C-N bond-forming crosscoupling reactions has concentrated on the formation of aromatic C-N bonds. Recent studies show that the application of cross-coupling reactions to alkenyl halides or triflates furnished enamines (Scheme 19) (for palladium-catalyzed reaction, see 28,28a-28d, and for copper-catalyzed reaction, see 28e-28g). Brookhart et al. studied the palladium-catalyzed amination of 2-triflatotropone 109 for the synthesis of 2-anilinotropone 110.28 It was found that the reaction of 109 proceeded effectively in the presence of racemic BINAP and a base. As a simple method for the synthesis of enamines, the palladium-catalyzed reactions of alkenyl bromide 111 with secondary amine were achieved under similar conditions.2841 The water-sensitive enamine 112 was isolated as pure compound after dilution with hexane and filtration through Celite. The intramolecular cyclization of /3-lactam 113, having a vinyl bromide moiety, was investigated by Mori s... [Pg.707]

An application of Stille couplings to the solid phase using a traceless A-glycerol linker with 2-stannylindoles has been developed [177]. Only a few examples of the use of 3-stannylindoles in Stille reactions have been described. Ortar and co-workers prepared 169 and 170 and effected Pd-catalyzed cross coupling reactions with several aryl, heteroaryl, and vinyl substrates (bromides, iodides, triflates) to give the expected products 171 in high yields [178]. Enol triflates behave exceptionally well under the Ortar conditions, e.g., 172 to 173. [Pg.110]

Na2CC>3), 25 °C, 24 h. Larock extended his work in several ways [302-305], particularly with regard to Pd-catalyzed cross-coupling of o-allylic and o-vinylic anilides with vinyl halides and triflates to produce 2-vinylindoles [303-305], an example of which is shown [305]. The related "Larock indole synthesis" is discussed separately in the next section. [Pg.136]

Both vinyl- and aryl triflates have been cross-coupled with 2-furylzinc chloride [26-28]. Since vinyl triflates are easily obtained from the corresponding ketones, they are useful substrates in Pd-catalyzed reactions. In the following example, a Negishi coupling of 2-furylzinc chloride and indol-5-yl triflate (22) provided an expeditious entry to 2-(5 -indolyl)furan (23). Protection of the NH in the indole ring was not required. A similar reaction was successful with pyridyl- and quinolinyl triflates. [Pg.272]

Recent contributions from Vogel s group have shown that, under CO atmosphere and in the presence of Pd2(dba)3 and Ph3As, 1-stannyl glycals can be carbonylated and coupled to organic halides (Scheme 6a),38 or vinyl triflates (Scheme 6b),39 in carbonylative Stifle cross-coupling processes.40 Also of interest is the palladium catalyzed cross-coupling reaction of... [Pg.293]

Scheme 6 Carbonylative Stille cross-coupling of vinyl halides, triflates, and sulfonyl chlorides. Scheme 6 Carbonylative Stille cross-coupling of vinyl halides, triflates, and sulfonyl chlorides.
As well as alkenylstannanes [106-108], other classes such as a-heteroatom-substituted alkyltributylstannanes [109] and, more importantly, allylic stannanes [110, 111] also undergo these Sn-Cu transmetalations. Otherwise difficult to prepare, allylic copper reagents may, however, be obtained by treatment of allylic stannanes (produced in turn from organolithium, magnesium, or zinc organometallics) with Me2CuLi LiCN. They enter into cross-coupling reactions with alkyl bromides [110] or vinyl triflates (Scheme 2.52) [111]. [Pg.68]

The 2-formyl-ip-methylcarbapenem 62 has been obtained in five steps from a readily available P-lactam in 23-26% overall yield <98MI1294>. Suzuki-Miyaura cross-coupling of aiylboronic acids and vinyl triflates is a convenient route to 2-aiylcarbapenems on a small scale but may present problems on a large scale. Vinyl phosphates, mesylates or tosylates are convenient alternatives to triflates <9981471>. Radical cyclizations of readily available enyne-2-azetidinones (e.g., 63) with a tin hydride, RjSnH, provides a route to the... [Pg.85]

Alkyl halides possessing / -hydrogens are usually poor substrates for carbonylative cross-coupling due to competitive / -hydride elimination/ Allyl chlorides can be used in carbonylative cross-coupling with allylstannanes/ phenyl-, 3-furyl, or vinylstannanes " to afford allylketones in modest to good yields. Divinylketones can be accessed through the reaction of vinylstannanes with vinyl iodides or vinyl triflates, with the latter requiring the addition of LiCl. Synthetic potential of this method has been proved in the formation of macrocyclic ketone jatrophone. In the reaction of vinyl triflates with tetramethyltin or aryltrimethylstannanes the additional activation by ZnCle is required. [Pg.413]

It was also discovered that aryl and vinyl iodides, bromides, and triflates participated efficiently in cross-coupling reactions with organostannanes when catalyzed by palladlum-on-carbon in the presence of Cu(l) as cocatalyst.1... [Pg.139]

Cross-coupling reactions of alkenylsilicates 114 with aryl or vinyl halides or triflates are catalyzed by a palladium complex to give the corresponding alkenes (equation 92)173. [Pg.1826]

A different approach to azepine derivatives involved a Pd-catalyzed cross-coupling reaction of the vinyl triflate 49 with the a-alkoxyboronate 50 (R = H) to give 51 in 45% yield acid-catalyzed hydrolysis then gave the azepine derivative 52 and the fused azepine 53, although yields were modest (Scheme 5) <2002JOC7144>. [Pg.5]


See other pages where Vinyl triflates cross-coupling is mentioned: [Pg.270]    [Pg.112]    [Pg.183]    [Pg.593]    [Pg.595]    [Pg.598]    [Pg.109]    [Pg.33]    [Pg.1218]    [Pg.439]    [Pg.127]    [Pg.418]    [Pg.656]    [Pg.329]    [Pg.712]    [Pg.309]    [Pg.330]    [Pg.12]    [Pg.14]    [Pg.835]    [Pg.99]    [Pg.372]    [Pg.183]    [Pg.1825]    [Pg.734]    [Pg.175]    [Pg.112]    [Pg.61]   


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Triflates cross-coupling

Vinyl coupling

Vinyl triflate

Vinyl triflates

Vinylic couplings

Vinylic triflates

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