Suzuki cross-coupling reactions derivatives

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... 

The preparation of nonsymmetrically disubstituted derivatives was achieved in a multistep synthesis involving three Suzuki cross-coupling reactions and an iodination reaction as the key steps. It starts with a building block consisting of a... 

The Suzuki cross-coupling reaction is recognized as a novel, abbreviated method for the synthesis of 2-hydroxychrysene, 2-hydroxy-5-methylchrysene, and 8-hydroxy-5-methyl-chrysene from easily accessible reactants (Eq. (8)) [23]. These phenolic compounds constitute precursors for the synthesis of dihydrodiol and bay-region diol epoxide derivatives of chrysene and 5-methylchrysene, which are implicated as the active forms of carcinogenic polynuclear aromatic hydrocarbons. 

Most recently, Monteiro et al. have reported that cyclopalladated compounds derived from the ortho-metalation of benzylic tert-butyl thioethers are excellent catalyst precursors for the Suzuki cross-coupling reaction of aryl bromides and chlorides with phenylboronic acid under mild reaction conditions. A broad range of substrates and functional groups are tolerated in this protocol, and high catalytic activity is attained (Eq. (58)) [93]. 

Ferrocenyl-based ligands comprise a versatile class of auxiliaries because they can be easily modified at the benzylic position with retention of configuration and can incorporate both central and planar chiralities. The appropriate balance of steric and electronic factors has provided ferrocenyl derivatives featuring chelating P,N properties that proved beneficial in numerous enantioselective transformations [50]. Among more recent applications, they could be utilized very efficiently in Pd-catalyzed hydrosilylation (14 >99% ee) [51] and hydroboration (>94% ee) [52] of olefins, allylic amination (99 % ee) [53], Suzuki cross coupling reactions (Section 2.11) [54], and enamide hydrogenation (>99% ee) [55]. 

The crucial step in the total synthesis of arcyriacyanin A (67) by Tobinaga et al. [42] involved a Suzuki cross-coupling reaction between indoleborate 60 and 4-iodoindole (63). As outlined in Scheme 12, 4-iodo-l-tosyl-indole (62) was derived from 4-amino-l-tosyl-indole (61) by diazotization and iodination. Desulfonation of 62 with 40% NaOH in refluxing methanol led to... 

The cross-coupling reactions of various aryl halides and triflates with vinyl- or arylboronic acids and esters (Suzuki cross-coupling reaction) was also carried out in water in the presence of tetrabutylammonium bromide and a base such as Na2C03, using a phosphine-free palladium catalyst to give biaryl derivatives [Eq. 18)1 [108,109]. More recently, Casalnuovo [101] and Gen t [102,110] have performed this reaction using water-soluble palladium catalysts PdCla (tppms)2 and Pd(OAc)2/tppts in water/acetonitrile. 

Pyridazine boronic esters are substrates in Suzuki cross-coupling reactions. [4-I-2] Cycloaddition reactions of 1,2,4,5-tetrazine derivatives 1 with alkynyl boronic esters 257 provide easy access to functionalized pyridazine boronic esters 258. New unsymmetrical 1,2,4,5-tetrazines 259 and 261 have been prepared and tested in reactions with alkynyl boronic esters 257, providing the corresponding pyridazines 260 and 262 as single regioisomers (Scheme 64) <2005AGE3889>. 

The use of alkynyl pinacolboronic esters such as 17 afforded functionalized building blocks with high synthetic potential. The primary boron-functionalized dihydroaromatic intermediate could be used directly in a Suzuki cross-coupling reaction with 2,6-dimethoxyiodobenzene to afford the biphenyl derivative 18 in good yield, which was then converted into heterocycle 19 (Scheme 13.10) [10],... 

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