作者:Wei Wei、Xi-Jie Dai、Haining Wang、Chenchen Li、Xiaobo Yang、Chao-Jun Li
DOI:10.1039/c7sc04207h
日期:——
Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(II) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an
羰基的自然可用性为有效的烯烃合成提供了还原性羰基偶联的巨大合成潜力,但催化羰基的交叉偶联仍然很难实现。我们在本文中报道了在钌(II)催化下由肼介导的这种反应。该方法能够以分子间或分子内的方式使两种不对称羰基化合物容易且选择性地交叉偶联。此外,该化学物质可容纳多种底物,在温和的反应条件下以良好的官能团耐受性进行,并产生化学计量的良性副产物。重要的是,KO t Bu和双齿膦dmpe的共存对于这种转化至关重要。
Ni- or Cu-Catalyzed Cross-Coupling Reaction of Alkyl Fluorides with Grignard Reagents
alkyl Grignardreagents in both Ni- and Cu-catalyzed reactions. Alkylfluorides efficiently reacted with tertiary alkyl and phenyl Grignardreagents using CuCl2 in the absence of 1,3-butadiene to afford the coupling products in high yields. The competitive reaction of a mixture of alkyl halides (R-X; X = F, Cl, Br) with nC5H11MgBr showed that the reactivities of the halides increase in the order R-Cl
Consecutive Approach to Alkenes that Combines Radical Addition of Phosphorus Hydrides with Horner−Wadsworth−Emmons-Type Reactions
作者:Mark P. Healy、Andrew F. Parsons、James G. T. Rawlinson
DOI:10.1021/ol050292e
日期:2005.4.14
the phosphonothioate and reaction with a ketone, offers a concise one-pot approach to substituted alkenes. This novel method, which can incorporate alkylation or acylation steps, can be applied to the stereoselective formation of sterically hindered tri- and tetrasubstituted alkenes.
The dimesitylboron group in organic synthesis. 4. The ‘boron Wittig’ reaction
作者:Andrew Pelter、Bakthan Singaram、John W. Wilson
DOI:10.1016/s0040-4039(00)81484-7
日期:1983.1
Anions generated α- to a dimesitylboron group readily condense with aldehydes and ketones. Elimination of Mes2BOLi then leads to alkenes in a boron analogue of the Wittig reaction.
Hindered organoboron groups in organic chemistry. 23. The interactions of dimesitylboron stabilised carbanions with aromatic ketones and aldehydes to give alkenes.
Dimesitylboron stabilised carbanions react with diarylketones to give the corresponding alkenes in mild conditions with good yields. Reactions with aromatic aldehydes are more complex, but in all cases E-alkenes are available in good yields by trapping the intermediates with chlorotrimethylsilane followed by treatment with aq. HF/CH3CN. Treatment of the same intermediates with trifluoroacetic anhydride