Transition-Metal-Free Synthesis of 1,2,3-Trisboronates and Continuous Flow Application to Boronates Preparation from Oxygen-Rich Feedstocks

Oxygen-rich compounds are abundant in nature, forming the structural backbone of many bio-derived feedstocks. While these functionalities offer diverse reactivity, their inherently strong C–O bond dissociation energies have historically posed a significant challenge to deoxygenative transformations. Among emerging strategies to address this, deoxygenative borylation has gained growing attention for its ability to convert oxygen-rich precursors into boron-containing products—versatile intermediates in synthetic chemistry. Despite this potential, adjoined polyboronates remain scarce and underexplored, particularly from renewable building blocks.This thesis delineates the preparation of adjoined polyboronates from naturally occurring, readily available oxygen-rich precursors. Chapter 2 describes the use of allylic alcohols to access 1,2,3-trisboronates, with an emphasis on fine-tuning reaction selectivity to favor their formation without the assistance of transition-metal catalysts. Transition-metal-free protocols are particularly attractive in this context, as they avoid reliance on costly or scarce metals, minimize environmental and toxicity concerns, and simplify purification—advantages that align with the broader goal of sustainable synthesis from renewable feedstocks. The synthetic utility of the resulting boronates was briefly explored to highlight their downstream applicability. Chapter 3 advances this methodology by developing a streamlined, additive-free and metal-free synthesis of 1,2,3-trisboronates, simplifying the reaction procedure and improving accessibility. Chapter 4 shifts focus to continuous-flow chemistry, leveraging its operational efficiency and scalability for the sustainable production of these polyboronates. Chapter 5 expands the scope of the established flow system to accommodate the deoxygenative borylation of carbonyl compounds—another abundant oxygen-rich functional group—demonstrating high throughput under optimized conditions. While the aldehyde studies revealed inconsistencies between crude and isolated yields, these findings highlight the opportunity for integrating real-time analytical tools to better capture reaction dynamics and further refine purification strategies. Ultimately, these studies provide both the methodological foundation and operational framework for the synthesis of adjoined trisboronates from renewable resources. By combining transition-metal-free protocols with scalable continuous-flow platforms, this work demonstrates how methodology development can be directly connected to practical, gram-scale synthesis. The results not only highlight the versatility and adaptability of the system but also point to opportunities for further refinement through real-time analysis and expanded substrate scope. In doing so, this thesis lays the groundwork for sustainable and modular synthetic routes to structurally diverse boron architectures, hoping to open new avenues for innovation in the synthesis and scalable production of complex boron architectures.