Tsuji-Trost reaction substrate compounds

The catalytic version of allylation of nucleophiles via 7r-allylpaUadium intermediates was discovered in 1970 using allylic esters and aUyl phenyl ethers as substrates (Scheme Formation of 7r-allylpaUadium complexes by oxidative addition of various allylic compounds to Pd(0) and subsequent reaction of electrophilic rr-allylpalladium complexes with soft carbon nucleophiles are the basis of the catalytic allylation. After the reaction, Pd(0) is regenerated, which undergoes oxidative addition to the allylic compounds again, making the whole reaction catalytic. The efficient catalytic cycle is ascribed to the characteristic feature that Pd(0) is more stable than Pd(II). Allylation of carbon nucleophiles with allyhc compounds via TT-allylpalladium complexes is called the Tsuji-Trost reaction. The reaction has wide synthetic applications, particularly for cyclization. " ... 

Another potent cytotoxic compound cristatic acid (38) was prepared for the first time by A. Fiirstner. Allylation of vinyl epoxide 35 with bis(phenylsulfonyl)methane (36) gave 1,4-diol 37 in almost quantitative yield. This substrate was subsequently elaborated to cristatic acid (38). This example nicely highlights the use of the vinyl epoxide activating group in Tsuji-Trost reactions. 

The Pd(0)-catalyzed allylic alkylation developed by Tsuji and Trost is useful for creating organic frameworks that have a variety of polar functional groups (197). The reaction is formally viewed as a combination of an allylic cation and a carbanion. A number of allylic compounds that have an electronegative leaving group can be coupled with stabilized cafbanions of pKa less than 16 under mild reaction conditions (Scheme 84). Nucleophilic attack of Pd(0) species on an allylic substrate... 

It was not long after the original work on the Trost-Tsuji reaction that asymmetric examples were reported.60 In recent years, numerous cases have appeared where this reaction was used to create chiral substituted allylic compounds in high % ee. Enhancement of chirality in allyl substrates is challenging because chemistry on the allylic ligand occurs remotely from the chiral ligand also attached to the metal. There are several different points in the catalytic cycles depicted in Schemes 12.10a and b where asymmetric induction could occur.61 These scenarios include the following ... 

In contrast to the processes based on the external attack of a nucleophile on the coordinated CO or olefin ligands on Pd(II) species, where re-oxidation of the Pd(0) produced to reactive Pd(II) presents a considerable problem, no such problem is involved in reaction of a Pd(0) complex with allylic substrates. As we have already discussed in Schemes 1.9 and 1.10, allylic compounds such as allylic acetates or carbonates readily oxidatively add to Pd(0) species to form 7 -allyl palladium(II) complexes that are susceptible to nucleophilic attack. The catalytic process converting allylic substrates to produce allylation products of nucleophiles has found extensive uses in organic synthesis, notably in the work of Tsuji and Trost. Employment of a chiral ligand in the catalytic allylation of nucleophiles allows catalytic asymmetric synthesis of allylation... 

The use of palladium(II) 7i-allyl complexes in organic chemistry has a rich history. These complexes were the first examples of a C-M bond to be used as an electrophile [1-3]. At the dawn of the era of asymmetric catalysis, the use of chiral phosphines in palladium-catalyzed allylic alkylation reactions provided key early successes in asymmetric C-C bond formation that were an important validation of the usefulness of the field [4]. No researchers were more important to these innovations than Prof. B.M. Trost and Prof. J. Tsuji [5-10]. While most of the early discoveries in this field provided access to tertiary (3°) stereocenters formed on a prochiral electrophile [Eq. (1)] (Scheme 1), our interest focused on making quaternary (4°) stereocenters on prochiral enolates [Eq. (2)]. Recently, we have described decarboxylative asymmetric allylic alkylation reactions involving prochiral enolates that provide access to enantioenriched ot-quatemary carbonyl compounds [11-13]. We found that a range of substrates (e.g., allyl enol carbonates,... 

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