The Suzuki-Miyaura reaction is one of the most powerful tools for the formation of carbon-carbon bonds in organic synthesis. The utilization of alcohols in this powerful reaction is a challenging task. This short review covers progress in the transition-metal-catalyzed Suzuki--Miyaura-type cross-coupling reaction of pi-activated alcohol, such as aryl, benzylic, allylic, propargylic and allenic alcohols, between 2000 and June 2019.

Optically pure alcohols are abundant in nature and attractive as feedstock for organic synthesis but challenging for further transformation using atom efficient and sustainable methodologies, particularly when there is a desire to conserve the chirality. Usually, substitution of the OH group of stereogenic alcohols with conservation of chirality requires derivatization as part of a complex, stoichiometric procedure. We herein demonstrate that a simple, inexpensive, and environmentally benign iron(III) catalyst promotes the direct intramolecular substitution of enantiomerically enriched secondary and tertiary alcohols with O-, N-, and S-centered nucleophiles to generate valuable 5-membered, 6-membered and aryl-fused 6-membered heterocyclic compounds with chirality transfer and water as the only byproduct. The power of the methodology is demonstrated in the total synthesis of (+)-lentiginosine from D-glucose where iron-catalysis is used in a key step. Adoption of this methodology will contribute towards the transition to sustainable and bio-based processes in the pharmaceutical and agrochemical industries.

A nickel-catalyzed C(sp(3))-C(sp(2)) Suzuki cross-coupling of arylboronic acids and (hetero)naphthyl alcohols has been developed. A Ni(dppp) Cl-2 complex showed the highest efficiency and broadest substrate scope. High functional group tolerance has been achieved where 35 compounds could be generated in good to excellent yields, including both primary and secondary benzylic alcohols. Mechanistic studies using multiple NMR techniques as well as ESI-HRMS showed that the C-O cleavage is facilitated by an activation of the benzylic alcohol through formation of a boronic ester intermediate.

Nonactivated phenols have been employed as nucleophiles in the allylation of nonderivatized allylic alcohols to generate allylated phenolic ethers with water as the only byproduct. A Pd[BiPhePhos] catalyst was found to be reactive to give the O-allylated phenols in good to excellent yields in the presence of molecular sieves. The reactions are chemo-selective in which the kinetically favored O-allylated products are formed exclusively over the thermodynamically favored C-allylated products.

Palladium-catalyzed allylic substitution of non-derivatized enantioenriched allylic alcohols with a variety of uncharged N-, S-, C- and O-centered nucleophiles using a bidentate BiPhePhos ligand is described. A remarkable effect of the counter ion (X) of the XPd[kappa(2)-BiPhePhos][kappa(3)-C3H5] was observed. When ClPd[kappa(2)-BiPhePhos][eta(3)-C3H5] (complexI) was used as catalyst, non-reproducible results were obtained. Study of the complex by X-ray crystallography, (PNMR)-P-31 spectroscopy, and ESI-MS showed that a decomposition occurred where one of the phosphite ligands was oxidized to the corresponding phosphate, generating ClPd[kappa(1)-BiPhePhosphite-phosphate][eta(3)-C3H5] species (complexII). When the chloride was exchanged to the weaker coordinating OTf- counter ion the more stable Pd[kappa(2)-BiPhePhos][eta(3)-C3H5](+)+[OTf] (-) (complexIII) was formed. ComplexIII performed better and gave higher enantiospecificities in the substitution reactions. ComplexIII was evaluated in Tsuji-Trost reactions of stereogenic non-derivatized allylic alcohols. The desired products were obtained in good to excellent yields (71-98%) and enantiospecificities (73-99%) for both inter- and intramolecular substitution reactions with only water generated as a by-product. The methodology was applied to key steps in total synthesis of (S)-cuspareine and (+)-lentiginosine. A reaction mechanism involving a palladium hydride as a key intermediate in the activation of the hydroxyl group is proposed in the overall transformation.

A series of dibenzoarsole (also known as 9-arsafluorene) derivatives have been prepared, and their coordination chemistry has been investigated. The different ligand topology and the arsenic substituents govern the reactivity of the ligands. We report various crystal structures of palladium and platinum complexes derived from this family of ligands. The biphenyl backbone of the bridged bidentate ligands allows very flexible coordination. We have also studied the application of an allylic Pd complex in nucleophilic substitution reactions, revealing that the benzoarsole substituent is susceptible to metal insertion.