Arylboronic halogenation

The Suzuki reaction has proved extremely versatile and has found extensive use in natural product. synthesis. " Arylboronic acids [ArB(OH)2 are the usual substrates in this reaction together with arylhalides or triflates (Ar X, X = halogen... 

Coupling of Aryl Compounds With Arylboronic acid Derivatives Aryl-de-halogenation, and so on Aryl-de-boronylation, and so on... 

N-Unsubstituted y-sultams can be easily substituted at the nitrogen ring by alkylation, arylation or acylation. Arylation can be performed efficiently via copper promoted chemistry by using arylboronic acids. Alkylation is usually performed with halogen derivatives by using bases such as K2CO3, NaH, TEA. In some cases good results were obtained from hydroxy substituted compounds and DEAD/PPhs [59,60]. 

The cyclization can be carried out with halogenated amines, and substitution products of the new ring systems can also be obtained in the conventional way, by nitration, etc. Similar compounds can be prepared directly by using arylboron dichlorides in place of boron trichloride in the procedure indicated above. The parent borazarene derivatives, with hydrogen attached to boron, can be made from the B-hydroxy compounds with lithium aluminum hydride in the presence of aluminum chloride. N-Alkyl derivatives can be made either by using N-alkyl derivatives of the aminobiphenyls as starting materials, or by N-alkylation of the unsubstituted compounds via their N-lithio derivatives. Apart from their inherent interest, compounds of this type can serve as intermediates in various syntheses. Thus benzocinnolines and 2,2 -dihydroxybiphenyls can be obtained from derivatives of 2-aminobiphenyl. ... 

Ortho lithiation of arenes directed by CONRj, OCONRj, OMOM, or NHCOR (Eq. 5), or the halogen-lithium exchange reaction (Eq. 6) provides various aryllithiums regioselectively. In situ treatment of these lithium intermediates with trimethyl- or tri(isopropyl) borate gives variously functionalized arylboronic acids. Trapping aryl-lithium or aryl-magnesium intermediates with trimethylchlorosilane, followed by transmetallation to BClj or is a convenient alterna-... 

It is known that the halogen or OTf ligand on Ar-Pd-X is readily displaced by an alkoxy, hydroxy, or acetoxy anion to provide a basic Pd-OR complex. ° Indeed, the (hydroxo)palladium complex reported by Alper gives a cross-coupled product (70%) together with biphenyl (15%) (Eq. 20). The electronic effects of substituted arylboronic acids... 

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