Suzuki-Miyaura cross-coupling conditions

Since the discovery of the Suzuki-Miyaura cross-coupling reaction in 1979, the effect of various reaction parameters has been thoroughly studied, including bases, hgands, water, and various solvents [1, 2]. This section will outline new developments made over the past decades in further improving the Suzuki-Miyaura cross-coupling conditions. 

Organoboron compounds cannot react without proper activation. The use of oxygen bases is inherent in the standard Suzuki-Miyaura cross-coupling method. Fluorides (usually CsF) can be used as alternative activating agents, which is particularly useful in cases when the reagents are incompatible with oxygen bases for the reactions run under anhydrous conditions,24 (66) 241 Fluoride activation can be effective, however, even under aqueous phase-transfer conditions (67) 242... 

Vinylsilanes react with boron trichloride to give the corresponding borodesilylation products in good yield which, in turn, can be transformed into boronic esters 124 by alcoholysis (equation 102). The initial dichloroorganoborane products can be used directly in the Suzuki-Miyaura cross-coupling reaction192. Replacement of a carbon-silicon bond by a carbon-tin bond in fluorinated alkenes (e.g. 125) can be achieved by the reaction of silanes with Bu3SnCl and KF in DMF under mild conditions (equation 103)193. It is... 

Sequential Suzuki-Miyaura cross-couplings and Cadogan cyclizations were developed under microwave dielectric heating conditions to access a variety of 2-substituted carbazoles and other fused heterocyclic systems (Scheme 13). The use of microwave irradiation not only minimized the proto-... 

Transition metal mediated cross couplings of epoxides have remained relatively unexplored, with only a few examples of this potentially useful reaction reported in the literature. A recent report details the Suzuki-Miyaura cross-coupling of epoxides <07JOC3253>. The reaction of aryl epoxides with arylboronic acids under Suzuki-Miyaura coupling conditions provides the coupled product in good yields. Careful monitoring of the reaction is essential to avoid Pd-catalyzed rearrangement of the epoxides. 

Additionally, Suzuki-Miyaura cross coupling reactions can be performed on similar supported iodides. Aryl bromides could be employed in this reaction as well. After optimization of conditions, it turned out that a hydroxyl-derived IL was the best solvent for this reaction. Namely, reaction completion was obtained after 12 h at room temperature in [N11130H][NTf2] in the presence of 1% Pd(OAc)2 and using potassium carbonate as abase. Under these conditions, less than 1% of homocoupling product is observed and easily eliminated by washing with diethyl ether prior to transesterification with methanol. Overall, biphenyls were isolated under analytically pure form in 90-95% yields [126],... 

Anticipating a B-alkyl Suzuki-Miyaura cross-coupling reaction between the Cl-Cl 4 and C15-C24 subunits, alcohol 57 was smoothly converted to vinyl iodide 60 in seven steps, including a Pt02 reduction of the crowded triple bond of intermediate 59, without overreduction. The coupling of the vinyl iodide 60 and C15-C24 subunit was performed by using trialkyl boronate species 61, prepared from alkyl iodide 46, under [Pd(dppf)Cl2] and AsPhs conditions to afford the DDM backbone 62 in 60% yield (Scheme 14). Finally, after carbamate formation and total deprotection, DDM 1 was obtained in 70% yield. The spectroscopic and analytical data of the synthetic samples of as well as their in vitro cytotoxicity levels were in full accord with those of the natural product reported in the literature. 

Chem 663 46 2002] obtained high turnover numbers and turnover frequencies in Suzuki-Miyaura cross-coupling reactions at room temperature conditions with this catalyst. Botella Najera [J Org Chem 70 4360 2005] also studied this catalyst for Mirozoki-Heck couplings in aqueous A. iV-dimethylacetamide in air using N-methyldicyclohexylamine (see [7560-83-0]) as base with or without Bu4NBr. 

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