Chinese Journal of Chemistry最新文献

Comprehensive Summary

Cross-electrophile couplings (XEC), a crucial subset of cross-coupling reactions, center on the formation of robust C—C bonds through the union of two electrophiles. Usually, such reactions have primarily been catalyzed by transition metals. However, with the steady advancements in photochemical and electrochemical technologies, XEC reactions have significantly progressed and broadened their scope, allowing for the utilization of a wider array of tolerable functional groups, thus revealing vast application prospects. This review aims to systematically summarize the current prevalent types of electrophiles and delve into their specific application examples within XEC reactions involving electrophiles with identical functional groups. Specifically, XECs between the same type of halides have received considerable attention, whereas carboxylic acids and alcohols are still in the early stages of investigation. Furthermore, certain other common electrophiles remain unexplored in this context. Moreover, this review underscores the remarkable contributions of photochemistry and electrochemistry in the field of XEC reactions, aiming to provide valuable insights and inspiration for researchers. Also, this review hopes to spark further interest in XEC reactions, thereby fueling the continuous development and advancement of this exciting area of research.

Key Scientists

Since the 1960s, advancements in the XEC reaction have been substantial, driven primarily by the application of transition metal catalysts. In this area, many distinguished scientists have contributed their wisdom and efforts. Particularly noteworthy is that, during the systematic study of XEC reactions with the identical functional groups, in 2016, MacMillan achieved a photocatalytic XEC reaction between aryl bromides and alkyl bromides; in 2020, Weix successfully realized a nickel-catalyzed XEC reaction between aryl chlorides and alkyl chlorides. Concurrently, contributions from researchers such as Mei, Wolf, Sevov, Lin, Shen, Browne, Zhang, and Qiu have expanded the scope of XEC reactions to various halides. By 2022, MacMillan and Baran achieved a significant milestone in the XEC between carboxylic acids, further broadening the scope of research in this area. Also, advancements in the XEC of alcohols have been noted, with researchers including Weix, Lian, Tu, and Stahl conducting pioneering work and successfully executing the XEC of protective groups. It is foreseen that the ongoing research endeavors will primarily concentrate on the expansion of diverse electrophiles.

Vicinal stereogenic centers are ubiquitous structural scaffolds in both natural products and synthetic compounds, yet their enantioselective construction remains a significant challenge in organic synthesis. Organoboron compounds are of paramount importance in synthetic chemistry due to their ability to undergo facile transformations, yielding diverse essential chemical bonds such as carbon-carbon, carbon-oxygen, carbon-nitrogen, and carbon-halogen bonds. Transition-metal-catalyzed asymmetric borylative functionalizations of internal alkenes offer a promising strategy for the enantioselective installation of two adjacent chiral centers across carbon-carbon bonds. By leveraging the versatile transformations of the newly introduced boryl unit, this approach holds great potential for expanding the structural diversity of vicinal stereogenic scaffolds. In this concise review, we aim to highlight recent advancements in transition-metal-catalyzed asymmetric borylative functionalizations of internal alkenes, underscore their utility as a versatile approach for constructing vicinal stereogenic centers, and discuss unsolved challenges and future directions in this field.

Key Scientists

Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono-organoborons, the site-selective functionalization of poly(organoborons) has attracted substantial interest in organic synthesis, pharmaceuticals, and agrochemicals due to the presence of multiple potential reaction sites. This review discusses various activation modes of the target C–B bond, with diverse transformations being achieved in both a selective and efficient manner. Recent advances in the catalytic selective transformations of 1,n-diboronates through ionic and radical pathways are highlighted. Furthermore, we summarize the existing challenges and future research directions in this field.

Key Scientists

In 1993, Suzuki, Miyaura and coworkers developed a pioneering example of selective arylation towards cis-1,2-bis(boryl) alkenes, marking the inception of this field. The Morken group has made significant contributions to the asymmetric diboration of alkenes and realized elegant catalytic functionalization of these compounds since 2004. In 2016, Fernández and colleagues achieved the selective arylation of the internal C–B bond of tri(boronates). Since 2019, the Aggarwal group has developed efficient Giese-type addition and selective arylation at the more substituted C–B bond of 1,2-bis(boronic) esters through photoredox catalysis. The controllable regiodivergent alkynylation of 1,3-bis(boronic) esters was developed by Gao and coworkers in 2023. Recently, Qin conducted elegant research on the programmable late-stage functionalization of bridge-substituted bicyclo[1.1.1]pentane (BCP) bis-boronates. Since 2013, catalytic stereoselective transformations have been developed by several groups, including those led by Morken and Chen. This review summarizes the latest and most significant developments in this field since 1993.