<i>gem-</i>Difluoroolefination of Diazo Compounds with TMSCF<sub>3</sub> or TMSCF<sub>2</sub>Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors
作者:Mingyou Hu、Chuanfa Ni、Lingchun Li、Yongxin Han、Jinbo Hu
DOI:10.1021/jacs.5b09888
日期:2015.11.18
fragment resulting from a diazocompound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazocompounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazocompounds with TMSCF3, which possesses
A catalytic, metal-free O–H bondinsertion of α-diazoesters in water in the presence of B(C6F5)3·nH2O (2 mol %) was developed, affording a series of α-hydroxyesters in good to excellent yields. The reaction features easy operation and wide substrate scope, and importantly, no metal is needed as compared with the conventional methods. Significantly, this approach further expands the applications of
在存在B(C 6 F 5)3 · n H 2 O(2摩尔%)的条件下,开发了水中无催化的α-重氮酸酯插入金属的O–H键,从而获得了一系列的α-羟基酯。好到极好的产量。该反应具有易于操作和广泛的底物范围的特点,重要的是,与常规方法相比,不需要金属。重要的是,这种方法进一步扩展了B(C 6 F 5)3在耐水条件下的应用。
Synthesis of diversely functionalised 2,2-disubstituted oxetanes: fragment motifs in new chemical space
作者:Owen A. Davis、Rosemary A. Croft、James A. Bull
DOI:10.1039/c5cc05740j
日期:——
Novel oxetane motifs incorporating diverse functional groups on the ring are readily accessed by an O–H insertion/cyclisation strategy.
新颖的氧杂环结构,其中环上包含多种功能基团,可以通过氧-氢插入/环化策略轻松获得。
Copper on charcoal: Cu<sup>0</sup> nanoparticle catalysed aerobic oxidation of α-diazo esters
By using a charcoal supported nano Cu0 catalyst (Cu/C), a highly efficient oxidation of α-diazo esters to α-ketoesters with molecular oxygen as the sole oxidant has been developed. In the presence of the Cu/C catalyst, 2-aryl-α-diazo esters with both electron-donating and electron-withdrawing groups can be oxidized to the corresponding α-ketoesters efficiently. Furthermore, this Cu/C catalyst can catalyse
Rapid Assembly of Saturated Nitrogen Heterocycles in One-Pot: Diazo-Heterocycle “Stitching” by N-H Insertion and Cyclization
作者:Alexander J. Boddy、Dominic P. Affron、Christopher J. Cordier、Emma L. Rivers、Alan C. Spivey、James A. Bull
DOI:10.1002/anie.201812925
日期:2019.1.28
Methods that providerapidaccess to new heterocyclic structures in biologically relevant chemical space provide important opportunities in drug discovery. Here, a strategy is described for the preparation of 2,2‐disubstituted azetidines, pyrrolidines, piperidines, and azepanes bearing ester and diverse aryl substituents. A one‐pot rhodium catalyzed N–H insertion and cyclization sequence uses diazo