Hypervalent λ<sup>3</sup>-Bromane Strategy for Baeyer−Villiger Oxidation: Selective Transformation of Primary Aliphatic and Aromatic Aldehydes to Formates, Which is Missing in the Classical Baeyer−Villiger Oxidation
undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-lambda(3)-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate
Solvent- and catalyst-free <i>N</i>-formylations of amines at ambient condition: Exploring the usability of aromatic formates as <i>N</i>-formylating agents
作者:Shaikh Batuta、Naznin Ara Begum
DOI:10.1080/00397911.2016.1255334
日期:2017.1.17
and catalyst-free N-formylation protocol has been developed for amines (1s–21s) where aromaticformates (1r–6r) were used as the N-formylating agents. The amine substrates include both primary and secondary aromaticamines (1s–19s) as well as aliphatic amine (20s) and a primary amide (21s). Structures of both the aromatic formate and amine components strongly influenced the rate of the reaction and yield
The formyloxyl radical: electrophilicity, C–H bond activation and anti-Markovnikov selectivity in the oxidation of aliphatic alkenes
作者:Miriam Somekh、Mark A. Iron、Alexander M. Khenkin、Ronny Neumann
DOI:10.1039/d0sc04936k
日期:——
outer-sphere electrontransfer between the formyloxyl radical donor and the [CoIIIW12O40]5− polyanion acceptor forming a donor–acceptor [D+–A−] complex is proposed to induce the observed anti-Markovnikov selectivity. Finally, the overall reactivity of HC(O)O˙ towards hydrogen abstraction was evaluated using additional substrates. Alkanes were only slightly reactive, while the reactions of alkylarenes
过去,很少通过实验观察到甲酰氧基自由基HC(O)O 3,这些研究是在电子结构的背景下进行的理论光谱分析。缺乏方便的制备甲酰氧基自由基的方法,使得人们无法研究其对有机底物的反应性。最近,我们发现在甲酸/甲酸锂的阳极电化学氧化中形成了HC(O)O 3。使用[Co III W 12 O 40 ] 5-聚阴离子催化剂,可导致由苯形成甲酸苯酯。在这里,我们介绍我们对电化学原位反应性的研究用有机底物生成HC(O)O 3。根据实验和计算得出的哈米特线性自由能关系,与苯的反应和选择的取代衍生物表明,HC(O)O 3是亲电子的。HC(O)O 3与末端烯烃的反应明显有利于抗马尔可夫尼科夫氧化反应,产生相应的醛作为主要产物以及进一步的氧化产物。以1-己烯为代表的底物进行的可能的反应路径分析,有利于从烯丙基C–H键中抽出氢形成己烯丙基的可能性,然后强烈建议在C1位置进一步进攻第二个HC(O)O˙自由基。据推测,进一步的氧化产物主要是由于HC(O)O
Three step procedure for the preparation of aromatic and aliphatic difluoromethyl ethers from phenols and alcohols using a chlorine/fluorine exchange methodology
作者:William R. Dolbier、Fei Wang、Xiaojun Tang、Charles S. Thomoson、Linhua Wang
DOI:10.1016/j.jfluchem.2014.01.018
日期:2014.4
Difluoromethyl ethers are prepared from phenols in three steps via their respective formate ester derivatives. The formates are first converted to dichloromethyl ethers by treatment with PCl5. These ethers are then induced to undergo chlorine/fluorine exchange to form the respective difluoromethyl ethers. The chlorine/fluorine exchange is carried out by either a room temperature, solvolytic process using THF-5HF
carbonylation reactions. However, there are no catalytic synthetic procedures for their preparation. In this manuscript, we developed a convenient palladium‐catalyzed procedure for the synthesis of aryl formates. Good yields were achieved undermild reaction conditions with formic acid as the formyl source.