Suzuki coupling carbonylative

Fig. 43 Palladium-catalyzed tandem carbonylation/Suzuki coupling reactions...

Methylene)indolinones have also been prepared by a tandem Heck-carbonylation/Suzuki-coupling [165]. Even though this methodology was further developed with Pd(PPh3)4, the combination Pd(OAc)2/SlPr HBF4 showed comparable activity (Scheme 19). 

Scheme 4.3 Pd-catalyzed carbonylative Suzuki coupling of organoboranes with vinyl halides...

Langstrom and colleagues described the synthesis of C- and C-labeled ketones by palladium-catalyzed carbonylative Suzuki coupling [27]. Aryl triflates with methyl- or arylboronic acids, and a low concentration of CO were used in... 

Also in 2009, Cai et al. published a paper on the use of an MCM-41-supported bidentate phosphine palladium(O) complex as a catalyst to the carbonylative Suzuki coupling of aryl iodides with arylboronic acids [38, 39]. This procedure makes the recycling of palladium catalysts possible. 

Recently, Gelman and colleagues reported on a new bidentate phosphine ligand for palladium-catalyzed carbonylative Suzuki coupling reactions [42]. Aryl iodides and bromides were coupled with arylboronic acids in the presence of 0.01-1 mol % of the catalyst. Ketones have been produced with high selectivity in good yields (Scheme 4.24). 

Very recently, Beller and colleagues described a novel carbonylative coupling of benzyl chlorides with aryl boronic acids [43]. This was the first report on carbonylative Suzuki couplings of benzyl chlorides with arylboronic acids (Scheme 4.25). The reaction was carried out using a commercially available... 

Another example of a one-pot indole synthesis, which proceeds through a Heck carbonylation and a Suzuki coupling, is shown below. The reaction conditions are similar to the previous example however microwave heating is employed [174] (Scheme 6.54). 

Xia and co-workers synthesised a number of Pd-NHC complexes (33, 34, 36) for carbonylative Suzuki reactions (Fig. 9.6) [41], Various aryl iodides were carbonylatively coupled (P = 1 atm) with either phenylboronic acid or sodium tetraphenylborate. All the complexes were highly active, but 33 provided the best results with >76% selectivity for ketone in all the reactions. Xia followed this work with the double carbonylation of various aryl iodides with several secondary amines using the catalysts [CuX(Mes)] (37-X) and [Cu(IPr)X] (38-X) (X = I, Br, Cl) (3 MPa, 100°C, 10 h) (Scheme 9.7) [42],... 

The Fukuyama indole synthesis involving radical cyclization of 2-alkenylisocyanides was extended by the author to allow preparation of2,3-disubstituted derivatives <00S429>. In this process, radical cyclization of 2-isocyanocinnamate (119) yields the 2-stannylindole 120, which upon treatment with iodine is converted into the 2-iodoindole 121. These N-unprotected 2-iodoindoles can then undergo a variety of palladium-catalyzed coupling reactions such as reaction with terminal acetylenes, terminal olefins, carbonylation and Suzuki coupling with phenyl borate to furnish the corresponding 2,3-disubstituted indoles. 

The Suzuki coupling reaction of 2-haloselenophenes with boronic acids catalyzed by palladium salt is a new route to prepare 2-arylselenophenes and 2,5-diarylselenophenes in good yields. In addition, 2-arylselenophenyl ketones were also obtained by this protocol from 2-iodoselenophene and boronic acids via a carbonylative process [130],... 

Dihydro-277-thiopyran-6-yl trifluoromethanesulfonate undergoes a carbonylative Suzuki-Miyaura coupling with vinylboronic acids to give substituted 1 -(3,4-dihydro-2//-thiopyran-6-yl)prop-2-cn-l -ones together with minor amounts of the non-carbonylated coupled products <2007EJ02152>. 

Fig. 46 Light-stimulated palladium-catalyzed tandem radical cyclization/carbonylation/ Suzuki-Miyaura coupling reactions...

The boroxines could then be subjected to Suzuki coupling with aryl, vinyl, or benzyl halides. Suzuki coupling with tri- -butylstannyl chloride also gave the tri- -butylstannyl-substituted thiophenes 221. These can form the starting materials for further transformations. The carbonylative coupling with halides resulted in the formation of ketones tin-lithium exchange followed by reaction with electrophiles led to a host of other useful products (Scheme 65). 

Homogeneous, aqueous tv o-phase catalysis is also of industrial interest for the production of the important intermediate phenylacetic acid (PAA), -which is used in perfume and pesticides syntheses. The previous process (benzyl chloride to benzyl cyanide -with hydrolysis of the latter) suffered from the formation of large amounts of salt (1400 kg per kg of PAA). The new carbonylation method reduces the amount of salt by 60% and makes use of the great cost difference between —CN and —CO [79-81]. Finally, the Suzuki coupling of aryl halides and arylboronic acids, substituting Pd/TPPMS with Pd/TPPTS catalysts, should be also mentioned. 

This ester was developed for use as a protecting group for arylthiols that was compatible with Suzuki coupling conditions which typically use some form of base. Its increased stability is the result of steric protection of the carbonyl. 

Palladium-catalysed carbonylation of halides, with carbon monoxide, can be used to prepare esters, amides and ketones by trapping the intermediate acylpalladium halide with alcohols,amines and organometal-lics, respectively. Boronic acids are probably the best organometallics for the preparation of ketones, but conditions must be adjusted to give the best selectivity between the acylation reaction and simple Suzuki coupling of the boronic acid with the starting halide. ... 

The suitability of the homogeneous aqueous catalysts and thus the scope of application in general will be extended in commercial or pilot-plant operation to other central atoms and reactions such as Heck reactions and other carbonylations (with Pd), hydrogenations (Pd, Pt, Rh, Ir), formation of water-soluble polymers (Pd), vinylations, metathesis conversions (Ru), Suzuki couplings, etc. (cf. Section 6.6). 

Scheme 33. OZzgoarylenes [122 c] by Suzuki coupling and synthesis of unsymmetrical (hetero) biaryl ketones by Pd-catalyzed carbonylation [123]...

Boronic acids submit the organic groups to o-alkynylaryl isocyanates to afford 3-alkylideneoxindoles, the incoming group being cw-related to the carbonyl function. Bis(pinacolato)diboron reacts similarly, and apparently the cyclic adducts are available for Suzuki coupling to generate a library of oxindoles. ... 

Suzuki coupling under Pd(OAc>2 also catalyzes the Carbonyl compounds an tin(Il) chloride. ... 

Carbonylation and carboxylation. Araldehydes are derived from the Pd-catalyzed reaction of ArX with CO and HCOONa. The Suzuki coupling under CO leads to diaryl ketones. Chromones and quinolones are similarly acquired by carbonylation of o-iodophenols and anilines in the presence of alkynes. 2-Aryl-benzimidazoles and -benzothiazoles are produced from o-arenediamines and o-mercaptoanilines, respectively. 

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