Mondal Abdur Rouf Samim, Bapat Nakul Abhay, Mishra Harshita, Hari Durga Prasad
Department of Organic Chemistry, Indian Institute of Science Bangalore 560012 India
Chem Sci. 2025 Jun 4. doi: 10.1039/d5sc02288f.
Ring-strain-enabled transformations have made significant progress, pushed the boundaries of unexplored chemical space, and emerged as a powerful tool for constructing complex molecules selectively and efficiently. Among the strained ring systems, [1.1.1]propellane, bicyclobutane (BCB), and azabicyclobutane (ABB) have garnered substantial attention and found numerous synthetic applications. In contrast, the chemistry of bicyclo[2.1.0]pentane, commonly known as housane, is scantly explored due to the lack of modular synthetic approaches. Herein, we describe a highly stereoselective, catalytic strategy for synthesizing polysubstituted housanes with up to three contiguous all-carbon-quaternary centers. The reaction is very efficient, works under mild conditions, requires visible light and organic dye as a photocatalyst, and exhibits a broad substrate scope. Furthermore, we have also developed a highly diastereoselective Paterno-Buchi reaction for synthesizing spiro-oxa-housanes, which are novel molecular entities in the literature. The post-synthetic diversification of the products a strain-release driven diastereospecific 1,2-ester migration that allows the rapid synthesis of functionalized bicyclic imides further highlighted the synthetic utility of the current protocol. Combined experimental studies and computational investigations revealed the origin of the reactivity and stereoselectivity.
环张力驱动的转化取得了重大进展，拓展了未被探索的化学空间边界，并成为选择性和高效构建复杂分子的有力工具。在张力环体系中，[1.1.1]丙烷、双环丁烷（BCB）和氮杂双环丁烷（ABB）受到了广泛关注并发现了众多合成应用。相比之下，由于缺乏模块化合成方法，双环[2.1.0]戊烷（俗称屋烷）的化学性质鲜少被研究。在此，我们描述了一种高度立体选择性的催化策略，用于合成具有多达三个连续全碳季碳中心的多取代屋烷。该反应非常高效，在温和条件下进行，需要可见光和有机染料作为光催化剂，并且底物范围广泛。此外，我们还开发了一种高度非对映选择性的Paterno-Buchi反应来合成螺氧杂屋烷，这是文献中的新型分子实体。产物的合成后多样化 一种由应变释放驱动的非对映特异性1,2-酯迁移，可实现功能化双环酰亚胺的快速合成 进一步突出了当前方法的合成实用性。结合实验研究和计算研究揭示了反应性和立体选择性的起源。
