Fluorinated self-assembled monolayers (SAMs) have been utilized in a variety of applications such as transistors and optoelectronic devices. However, in most SAMs the fluorinated groups could not be positioned in high proximity to the surface due to steric effects. This limitation hinders the direct analysis of the impact of the fluorination level on surface properties. Herein, fluorinated aromatic N-heterocyclic carbenes (NHCs), with 1–5 fluorine atoms, were self-assembled on a gold substrate. These NHCs enabled the positioning of fluorinated groups in high proximity to the metal surface to identify the influence of the fluorination level on surface properties. Experimental measurements and theoretical calculations identified that all fluorinated NHCs formed SAMs and adopted a flat-lying adsorption configuration while anchored to the metal surface via Au adatom. A higher fluorination level induced a stronger interaction of the fluorinated side groups with the Au surface. The stronger interaction and surface proximity of the fluorinated side groups deteriorated the overall binding energy of the NHC due to the less-optimized adsorption geometry of the carbene carbon. Ultraviolet photoelectron spectroscopy measurements revealed that fluorinated NHC monolayers lowered the surface work function by up to 1 eV and induced an increase of 15–20° in the water contact angle. The impact on surface properties did not vary according to the fluorination level of NHCs, and similar values were measured for NHC with 1–5 fluorine atoms. It is therefore identified that dominant adsorbate–substrate interactions between the fluorinated side groups and the Au surface quenched the distinct impact of the fluorination level on surface functionality.

Spiro N-heterocycles, particularly aza-spiro piperidines, have shown significant promise in pharmaceutical applications due to their ability to enhance physicochemical properties. Despite their potential, the preparation of these complex structures poses significant challenges. To address this, we propose a one-pot dearomative spirocyclization reaction of ynamides. This method involves a copper-catalyzed carbomagnesiation reaction, achieving chemo-, regio-, and stereoselective formation of vinyl metal intermediates. Upon the addition of a Lewis acid, these intermediates undergo a regioselective nucleophilic dearomatization event, facilitating the synthesis of diverse aza-spiro dihydropyridine scaffolds with multiple functional handles. Various Grignard reagents, diverse ynamides, and acylating reagents have been explored. A subsequent hydrogenation reaction provides access to both partially and fully reduced spirocyclic frameworks, broadening the scope of spirocyclic structures with potential medicinal applications.

We present a comprehensive study on the conformational behavior of diversely substituted 4-fluorotetrahydrothiopyran derivatives. Through quantum chemical simulations including DFT as well as NBO and NPA analysis, we elucidate the pivotal role of electrostatic interactions, occasionally complemented by hyperconjugative interactions, in stabilizing axial fluorine conformers. Less polar conformers were occasionally obtained, attributed to the interplay of electrostatic and hyperconjugative interactions. Experimental validation through NMR spectroscopy aligns with the computational analysis, thus providing a coherent understanding of the structural dynamics of these compounds.

The Brook rearrangement is a valuable synthetic tool that facilitates the controlled construction of complex molecules. Conventionally, it generates carbanion intermediates utilized in subsequent functionalization reactions. In this Review, we will explore recent advancements in the Brook rearrangement that extend beyond the traditional functionalization reactions. Specifically, we will highlight its involvement in unusual bonds cleavage, annulation reactions, and dearomatization efforts. The novelty of this rearrangement is underscored by showcasing its most recent applications.