Bench‐Stable Sulfoxide‐Based Boronates: Preparation and Application in a Tandem Suzuki Reaction

Abstract

A set of novel aromatic and heteroaromatic bench‐stable sulfoxide‐based boronates was prepared. The structure of the boronates was established by means of X‐ray crystallography, and the prepared boronates were successively used in Suzuki cross‐coupling reactions under different conditions. We also developed a tandem Suzuki reaction so that a base is generated during the nucleophilic addition of Grignard reagents to 4‐bromobenzaldehyde. The formed intermediates were smoothly coupled with the prepared boronates and the boronic acids under external base‐free conditions.magnified image

trans-Dichlorobis(XPhos)palladium(II) Precatalyst for Suzuki–Miyaura Cross-Coupling Reactions of Aryl/Vinyl Sulfonates/Halides: Scope, Mechanistic Study, and Synthetic Applications

“… 16 In 2018, PdCl 2 (XPhos) 2 was also used as a precatalyst in Suzuki–Miyaura coupling reactions between sulfoxide-based boronates and few electron-poor aryl bromide partners ( Scheme 2 , eq 2). 17 In our hand, PdCl 2 (XPhos) 2 appeared salvaging in the development of the challenging Suzuki–Miyaura cross-coupling reaction with various 2-pyrrolyl tosylates ( Scheme 2 , eq 3), while mixtures of the XPhos ligand or other ligands with various Pd II/0 sources led to unreproducible or poor yields. 14 As a result, 2-aryl pyrrole derivatives were obtained in good to excellent yields, allowing the completion of the total synthesis of the rhazinilam natural product.…”

The Unexpected Chemistry of Thiacalix[4]arene Monosulfoxide

“…To our knowledge, only one example describes a similar structure in the thiacalixarene series [27]. The rarity of this structural motif is further emphasized by the fact that only one similar arylboronate complex is known in non-calixarene chemistry [28]. Thus, thiacalix [4]arene tetrasulfoxide reacts with Et 3 B in a toluene-DMSO mixture at reflux overnight (or even for several days) to produce the corresponding Et-B(-O-) 3 complex [27].…”