A rhodium(III)-catalyzed C–H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
Catalyst-Controlled [3 + 2] and [4 + 2] Annulations of Oximes with Propargyl Alcohols: Divergent Access to Indenamines and Isoquinolines
作者:Wanchun Gong、Zhi Zhou、Jingjing Shi、Bo Wu、Biyun Huang、Wei Yi
DOI:10.1021/acs.orglett.7b03546
日期:2018.1.5
Rhodium(III)- and iridium(III)-catalyzedC–H activation of oximes and coupling with propargyl alcohols is discussed. Depending on the catalyst, the reaction pathway switched between [3 + 2] and [4 + 2] annulations, thus giving divergent access to indenamines and isoquinolines in a one-pot and atom-economical manner. The hydroxyl group in the tertiary propargyl alcohol substrate was found to be crucial
Anthranil: An Aminating Reagent Leading to Bifunctionality for Both C(sp<sup>3</sup>)−H and C(sp<sup>2</sup>)−H under Rhodium(III) Catalysis
作者:Songjie Yu、Guodong Tang、Yingzi Li、Xukai Zhou、Yu Lan、Xingwei Li
DOI:10.1002/anie.201602224
日期:2016.7.18
nitrogenation suffered from simple amidation/amination with limited atom‐economy and is mostly limited to C(sp2)−H substrates. In this work, anthranil was designed as a novel bifunctional aminating reagent for both C(sp2)−H and C(sp3)−H bonds under rhodium(III) catalysis, thus affording a nucleophilic aniline tethered to an electrophilic carbonyl. A tridendate rhodium(III) complex has been isolated as the
Cobalt(III)-Catalyzed Dehydrative [4+2] Annulation of Oxime with Alkyne by CH and NOH Activation
作者:Malay Sen、Deepti Kalsi、Basker Sundararaju
DOI:10.1002/chem.201503643
日期:2015.10.26
Efficient, scalable cobalt‐catalyzed redox‐neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology is widely applicable and tolerates various functional groups including heterocycles. A stable Cp*CoIII neutral complex is employed as the catalyst for this redox‐neutral [4+2] annulation reaction, which progresses smoothly by way of a reversible
据报道,高效,可扩展的钴催化的氧化还原中性[4 + 2]环化易于获得的肟和炔烃。所开发的合成方法学广泛适用,并能耐受包括杂环在内的各种官能团。稳定的Cp * Co III中性络合物用作该氧化还原-中性[4 + 2]环化反应的催化剂,该反应通过可逆的环金属化反应顺利进行,而无需任何外部氧化剂,仅产生水作为副产物。
Nitrate promoted mild and versatile Pd-catalysed C(sp<sup>2</sup>)–H oxidation with carboxylic acids
C(sp2)–H bond oxidation of oximes or azobenzenes with diverse carboxylic acids has been developed. In contrast to the previous catalytic systems, this protocol features mild conditions (close to room temperature for most cases) and a broad substrate scope (up to 64 examples), thus constituting a versatile method to directly prepare diverse O-aryl esters. Moreover, the superiority of the nitrate additive