Suzuki cross coupling reaction

In one case, an unpurified sample of pyrrolyl-bisboronic ester 78, synthesized using conditions described by Masuda and coworkers (2000JOC164), was readily engaged in a Suzuki cross-coupling reaction (95JOC7508) with 5-bromoquinoline 77, giving the desilylated product 79 in 29% overall yield (2002JCS(Pl) 1320). 

Scheme 5.2-18 Pd-catalyzed Suzuki cross-coupling reaction in a [BMIM][BF4] ionic liquid.

The Suzuki cross coupling reaction features in a synthesis of 4-arylcoumarins from the 4-halogeno derivatives c96JCS(Pl)2591> and in a route to the thieno[3,4-c]coumarin (8) from which coumarin 3,4-quinodimethane (9) can be thermally generated <96T3117>. 

FuNn iONAL Group Tolerance of PdildbrO VIMes.HCI Catalyzed Suzuki Cross-Coupling Reactions of Aryl Chlorides with Phenyi.boronic Acid Derivatives... 

Sterically demanding, water-soluble alkylphosphines 6.10 and 6.11 as ligands have been found to have a high activity for the Suzuki coupling of aryl bromides in aqueous solvents (Eq. 6.35).115 Turnover numbers up to 734,000 mmol/mmol Pd have been achieved under such conditions. Glucosamine-based phosphines were found to be efficient ligands for Suzuki cross-coupling reactions in water.116... 

Synthesis of unprotected 4-aryl phenylalanine by Suzuki cross-coupling reactions. 

Scheme 6.21 One-pot nucleophilic substitutions and Suzuki cross-coupling reactions for the synthesis of nAChR antagonists.

In the chemistry described in Scheme 6.151, Coats and a group of researchers from Johnson and Johnson utilized successive reductive aminations and Suzuki cross-coupling reactions to prepare a 192-member library of tropanylidene benz-amides [295], This series of tropanylidene opioid agonists proved to be extremely tolerant with regard to structural variation while maintaining excellent opioid activity. 

A rapid MW-assisted palladium-catalyzed coupling of heteroaryl and aryl boronic acids with iodo- and bromo-substituted benzoic acids, anchored on TentaGel has been achieved [174]. An environmentally friendly Suzuki cross-coupling reaction has been developed that uses polyethylene glycol (PEG) as the reaction medium and palladium chloride as a catalyst [175]. A solventless Suzuki coupling has also been reported on palladium-doped alumina in the presence of potassium fluoride as a base [176], This approach has been extended to Sonogashira coupling reaction wherein terminal alkynes couple readily with aryl or alkenyl iodides on palladium-doped alumina in the presence of triphenylphosphine and cuprous iodide (Scheme 6.52) [177]. 

Zhang et al. reported the use of densely functionalized molecules through Suzuki cross-coupling reactions [65]. This synthesis involves the reductive amination of mucaholic acids to form the unexpected lactone (e.g., 82). Compound 82 can then be reacted with phenylboronic acid (83) to form the 2,3-diaryl-a, /J-unsaluralcd-y-lactone 84 as outlined in Scheme 19 in a 78% yield. A similar procedure is outlined in the work of Beilina et al. [66]. 

TMS group and the Suzuki cross-coupling reaction is again repeated. This sequential process allows for the introduction of different aromatic groups at positions 3 and 4 of the pyrrole system. The synthesis of the Furstner intermediate (6) is completed by removal of the sulfonamide group. 

This route involves the conversion of a 3,4-diiodopyrrole (139) to the corresponding 3,4-diboronate ester (140) followed by a bis Suzuki cross-coupling reaction with a bromoquinoline, which generates the halitulin core (141). This pyrrole (141) is then alkylated with a tosylated cycloazadecane to generate a pentasubstituted pyrrole (143), which is converted to halitulin by debenzylation under hydrogenolysis conditions. 

One of the obvious areas where flow chemistry comes into its own is in the arena of catalysed reactions and continuous processing. An excellent example of this is the Suzuki reaction (for recent reviews on the Suzuki Cross-Coupling reaction, see Miura 2004 Beilina et al. 2004 ... 

Abell utilized a Suzuki cross-coupling reaction on resin 153. Subsequent acid treatment effected cyclization to indole 154, which was readily cleaved with amines and alcohols to form potential libraries of amides and esters, respectively [162],... 

Copper-catalyzed Suzuki cross-coupling reactions using mixed nanocluster catalysts have been studied recently. Copper-based catalysts were shown to be effective as reagents that can present an inexpensive and environmentally friendly alternative to noble metal catalysts. In the hydrogenation of cinnamic acid to corresponding alcohol, the selectivity can be varied by doping Sn with Rh colloid catalysts. A selectivity of 86% was achieved using a colloidal Rh/Sn (Rh/Sn = 1.5 1) catalyst on... 

Figure 13.31. IMes and IPr carbene ligands for Suzuki catalysts Application of the Suzuki cross-coupling reaction...

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