Bisz Elwira, Szostak Michal
Department of Chemistry, Opole University, 48 Oleska Street, 45-052, Opole, Poland.
Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ, 07102, USA.
ChemSusChem. 2017 Oct 23;10(20):3964-3981. doi: 10.1002/cssc.201701287. Epub 2017 Oct 5.
Oxygen-based electrophiles have emerged as some of the most valuable cross-coupling partners in organic synthesis due to several major strategic and environmental benefits, such as abundance and potential to avoid toxic halide waste. In this context, iron-catalyzed C-O activation/cross-coupling holds particular promise to achieve sustainable catalytic protocols due to its natural abundance, inherent low toxicity, and excellent economic and ecological profile. Recently, tremendous progress has been achieved in the development of new methods for functional-group-tolerant iron-catalyzed cross-coupling reactions by selective C-O cleavage. These methods establish highly attractive alternatives to traditional cross-coupling reactions by using halides as electrophilic partners. In particular, new easily accessible oxygen-based electrophiles have emerged as substrates in iron-catalyzed cross-coupling reactions, which significantly broaden the scope of this catalysis platform. New mechanistic manifolds involving iron catalysis have been established; thus opening up vistas for the development of a wide range of unprecedented reactions. The synthetic potential of this sustainable mode of reactivity has been highlighted by the development of new strategies in the construction of complex motifs, including in target synthesis. The most recent advances in sustainable iron-catalyzed cross-coupling of C-O-based electrophiles are reviewed, with a focus on both mechanistic aspects and synthetic utility. It should be noted that this catalytic manifold provides access to motifs that are often not easily available by other methods, such as the assembly of stereodefined dienes or C(sp )-C(sp ) cross-couplings, thus emphasizing the synthetic importance of this mode of reactivity.
由于具有一些重大的战略和环境优势，如资源丰富以及有潜力避免产生有毒卤化物废物，基于氧的亲电试剂已成为有机合成中一些最有价值的交叉偶联伙伴。在这种背景下，铁催化的C-O活化/交叉偶联因其天然丰度、固有的低毒性以及出色的经济和生态特性，在实现可持续催化方案方面具有特别的前景。最近，通过选择性C-O裂解开发耐官能团铁催化交叉偶联反应的新方法取得了巨大进展。这些方法通过使用卤化物作为亲电伙伴，为传统交叉偶联反应建立了极具吸引力的替代方法。特别是，新型且易于获得的基于氧的亲电试剂已成为铁催化交叉偶联反应的底物，这显著拓宽了该催化平台的范围。涉及铁催化的新机理体系已经建立；从而为开发一系列前所未有的反应开辟了前景。在构建复杂结构单元（包括目标合成）方面新策略的发展突出了这种可持续反应模式的合成潜力。本文综述了基于C-O亲电试剂的可持续铁催化交叉偶联的最新进展，重点关注机理方面和合成应用。应当指出，这种催化体系能够获得其他方法通常难以得到的结构单元，例如立体定向二烯的组装或C(sp)-C(sp)交叉偶联，从而强调了这种反应模式的合成重要性。
