Cross-coupling reactions with

The von Richter cinnoline process was further extended to solid-phase synthesis. The route began from benzylaminomethyl polystyrene and the required diverse o-haloaryl resins represented by 21 were prepared from substituted o-haloanilines. A Pd-mediated cross-coupling reaction with 21 and the alkynes provided the alkynylaryl derivatives represented by alkyne 22. The von Richter cyclization reaction with hydrobromic or hydrochloric acid in acetone/HaO and cleavage from the resin occurred in the same step to furnish the cinnoline derivatives 23 in 47-95% yield and 60-90% purity (no yield reported for each entry). 

Z)-3-(Tributylstannyl)allylamine participates in a palladium-catalyzed cross-coupling reaction with 2-bromobenzaldehyde (73, R = H) to give 3//-2-benzazepine (75, R = H). A similar reaction with the corresponding acetophenone 73 (R = Me) produces 1 -methyl-3//-2-benzazepine (75 R = Me), whereas with ethyl 2-bromobenzoate (73, R = OMe), 3//-2-benzazepin-(12/7)-one (74) is formed.237... 

In a very recent work, the Pd-catalysed cross-coupling reactions with arenediazonium salts under aerobic conditions in the presence of a chiral monothiourea ligand were reported (Scheme 25) [106]. Even if this Hgand bears four chiral centres, no test in asymmetric Heck-type reaction has been described so far. 

Scheme 6/1.62. Cross-coupling reactions with indium compounds.

Branchaud and coworkers have used cobaloximes as alkyl radical precursors for the cross-coupling reaction with nitronates.57 This method is very useful for producing branched-chain monosaccharides, as shown in Eq. 5.39.57b... 

Cross-coupling reactions with Zn acetylenides are the most convenient and selective routes to terminal acetylenes. In this reaction Zn is markedy superior to other metals, including Sn (24).116 The higher reactivity of Zn acetylides allowed assembly of hexaethynylbenezenes in two steps, with the last three groups introduced at the second stage by the Negishi reaction (25).117... 

Triarylbismuth compounds can be used in cross-coupling reactions with aryl iodides, bromides, or triflates in the presence of Pd(PPh3)4 and CsF or K2C03.174... 

Intramolecularly coordinated A1 and In compounds (e.g., (75), (76)) transfer the Me group in cross-coupling reactions with various aryl halides, including chlorides, catalyzed by Pd and Ni complexes.16 262 265 Monoorganobismuth compounds are reactive in cross-coupling reactions only if they contain an intramolecularly coordinating residue (77),266 267... 

There are only a few examples of displacement of a fluorine atom in a cross-coupling reaction. With tricarbonylchromium complexes of fluoroarenes as substrates, cross-coupling with both boronic acids and vinylstannanes has been realized. Interestingly, only PMe3 is effective as ligand in this reaction (89).2" See Section 9.6.3.4.10 for an example of the involvement of unactivated fluoroarenes in cross-coupling reactions. 

Aromatic and vinylic sulfides take part in cross-coupling reactions with Grignard reagents in the presence of Ni catalysts.336,337 This reaction has been applied to the enantioselective synthesis of binaphthyls using a standard chiral oxazoline ligand (Equation (25)) 338... 

Chlorophenyl)-4-phenyl-l,2,5-thiadiazole 128 was prepared from 3-trifluoromethylsulfonyloxy-4-phenyl-1,2,5-thiadiazole 127 by palladium-catalyzed cross-coupling reaction with the tributyl(4-chlorophenyl)stannane (Equation 20) <1996H(43)2435>. The addition of lithium chloride improves the yield. The 3-chloro- and 3-bromo-l,2,5-thiadiazole derivatives were also reactive, but only the bromo compound gave the product in comparable yield (see Section 5.09.7.6). 

Trialkylvinylstannanes undergo cross-coupling reactions with acyl chlorides, as shown by reactions 58307 and 59308. These acylations can be conducted under reductive conditions to saturate the carbon-carbon double bond, as illustrated in reaction 60309. Also... 

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. 

Cross-coupling reactions with organometallic reagents... 

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. 

The parent 2-tributylstannylpyridine has been used in cross-coupling reactions with aryl iodides [66], bromobenzyl phosphonates [67], and bromophosphinine 81, although the lifetime of mono-coupled pyridylphosphinine 82 was rather short [68]. Moreover, ample examples have been found for the cross-coupling of pyridylstannanes with halothiophenes [69-71], halothiazoles [72], halopyrimidines [45], halofuran, and halopyrroles [73]. 

The use of an organoindium glucal in palladium catalyzed [Pd(PPh3)2] cross-coupling reactions with aryl iodides gave moderate yields (40-60%) of C-l aryl glucals.45... 

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