Intramolecular Suzuki-Miyaura coupling

Lobregat, V. Alcaraz, G. Bienayme, H. Vaultier. M. Application of the resin-capture-release methodology to macrocyclisation via intramolecular Suzuki-Miyaura coupling. J. Chem. Soc. Chem. Commun. 2001. 817-818. 

Secondary phosphine oxides were used as ligands/preligands in palladium catalysts that were useful in the Suzuki-Miyaura coupling, in intramolecular ot-arylations of amides and in the arylation of indoles. ... 

Intramolecular palladium-catalyzed alkylations of (hetero)arenes have been pioneered by Wong and Song [25], who described in 1994 a direct benzylation of furans within a domino sequence starting with the intermolecular Suzuki- Miyaura coupling of furylboroxines with o-bis(bromomethyl)arenes (Scheme 19.14). Mixtures of the cross-coupled product and the corresponding homocoupled furan were almost always obtained. 

Scheme 19.14 Domino palladium-catalyzed Suzuki-Miyaura coupling/intramolecular C-H benzylation.

Naphthosumanenes 50-53, having a more ring-fused structure, are synthesized. The synthetic scheme includes the following three steps (1) bromination of the arene periphery, (2) introduction of 2-formylphenyl moiety by Suzuki-Miyaura coupling, and (3) intramolecular condensation in the presence of base. Mono-, di-, and tri-naphthosumanenes 50-53 are synthesized based on the strategy (Scheme 3.42) [137]. Bowl-to-bowl inversion of dideuteriomononaphthosumanene (32.2 kcal mol ) is much slower than sumanene. The structural optimization of naphthosumanenes shows the deeper bowl structures [129, 137],... 

Intramolecular carbopalladation of (124), followed by cross-coupling with aryl and vinyl fluoroborates, has been developed. The reaction outcome was rationalized by the initial i yn-addition to generate the Pd complex (125), which then undergoes the Suzuki-Miyaura coupling to produce (126). ... 

A novel macrocyclization procedure involving ttvo distinct cross-coupling manifolds in a domino fashion has been reported by Zhu for the synthesis of bipheno-mycin model 86 [56]. Thus, treatment oflinear feis-iodide with fois(pinacol)diborane (37) in the presence of Pd(dppf)2Cl2 under defined conditions affords the biphenyl macrocyclic compound 86 in 45% yield through a Miyaura aryl boronic ester formation followed by its intramolecular Suzuki cross-coupling. The diiodide containing a free phenol function (R=H) gave the macrocycle (R=H) in only 22-25% yield under these conditions (Scheme 3.37). 

Scheme 3.68 Intramolecular macrocyclization via Suzuki-Miyaura coupling.

As for the biaryl ether containing macrocycles, an array of bioactive macrocycles with an endo aryl-aryl bond exist in nature. A new palladium catalyzed reaction has been recently developed in which bis(pinacolato)diborane(4) mediated the process to reach such a structural motif. The reaction consists of a domino process involving a Miyaura s arylboronic ester synthesis and an intramolecular Suzuki-coupling. Synthesis of a bicyclic A-B-O-C ring system of RP-66453 273, a neurotensine receptor antagonist, with an endo aryl-aryl and an endo aryl-aryl ether bond was described (Scheme 53).141... 

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