有机硼在有机合成及功能分子中扮演重要角色。传统有机硼合成通常在反应最后一步引入硼原子，存在官能团耐受性差，所得产物结构相对简单等缺点。区别于传统的sp2杂化硼，sp3有机硼具有稳定性更好、更容易分离操作以及可兼容多种反应条件等特征。申请人提出了有机硼合成中的“沉默-活化”策略，即先将底物中的硼保护为sp3杂化态，在此基础上借助硼特殊的立体化学性质对底物进行活化，实现新颖的有机硼构建方法。基于此策略，申请人前期发展了系列基于sp3硼取代烯（炔）烃的新颖化学转化，并发现了多种sp3硼对底物的活化模式。本项目拟继续探究sp3硼取代不饱和体系，包括烯（炔）烃，烯（炔）丙基和卡宾的新颖反应活性。通过重排反应，迁移反应，金属催化反应，自由基反应，卡宾反应等对不饱和体系进行区域和化学选择性的高值转化，实现结构复杂，取代多样的有机硼构建新方法。本项目的实现将为有机硼的高效构建提供新思路。前期工作基础扎实。

Organoborons are arguably the most important organometallic reagents in organic synthesis. Besides, the boron atom is widely present in functional molecules. Classic synthesis of organoborons relies on the nucleophilic addition of organometallic reagents to alkylboronates or hydroboration of unsaturated bonds. The harsh reaction conditions typically employed result in poor functional group tolerances. As such, the boron moiety is usually introduced in the last step of the synthetic route and the product is typically simple in structure. Different from the traditional sp2-hybridized organoborons, sp3-B organoborons are stable, easy to separate and handle, and are compatible with diverse reaction conditions. These features enable the late-stage modification of sp3-B organoboron feasible. We proposed a novel “silence-activation” strategy towards organoboron synthesis. In this strategy, the boron atom in the organoboron substrate is firstly protected in a sp3-B form. The unique electronic and steric properties of sp3-B will then confer interesting reactivity to the pre-borylated substrate. Following this strategy, we have previously achieved several novel transformations towards the synthesis of organoborons via the functionalization of sp3-B-fabricated olefins and alkynes. Indeed, several activation modes from sp3-B to the substrate have been discovered. On the basis of these advances, future effort will continue on the development of new synthetic methods for sp3-B organoboron synthesis via the chemo- and regioselective transformations of sp3-B-substituted unsaturated system, including alkenes, alkynes, carbenes, allyl and propargylic groups. Key synthetic technologies in this project include rearrangement reaction, sigmatropic migration reaction, transition metal-catalyzed reaction, radical reaction and carbene reaction. The stability and unique activation effect of sp3-B on the substrate will confer interesting reactivities to the born-fabricated molecules. The fulfillment of this project will streamline a wide variety of organoborons synthesis and may stimulate many additional studies in this area. Good preliminary results have been obtained.