Rhodium(I)-Catalyzed Ene-Allene Carbocyclization Strategy for the Formation of Azepines and Oxepines
摘要:
A novel strategy for the preparation of seven-membered heterocyclic compounds has been realized. Treatment of ene-allene 1 with a catalytic quantity of rhodium biscarbonyl chloride dimer affords the cyclization product 2 in moderate to high yields. The scope and limitations of this new method are currently under investigation, and the results obtained to date are discussed within.
Direct Tryptophols Synthesis from 2-Vinylanilines and Alkynes via C≡C Triple Bond Cleavage and Dioxygen Activation
作者:Tao Shen、Yiqun Zhang、Yu-Feng Liang、Ning Jiao
DOI:10.1021/jacs.6b08094
日期:2016.10.12
metal-free C≡C triple bondcleavage, dioxygen activation, and reassembly into tryptophol derivatives has been developed. This chemistry provides a novel, simple, and efficient approach to highly valuable tryptophol derivatives from simple substrates under mild conditions. The mechanistic studies may promote the discovery of new methodologies through C-C bondcleavage and dioxygen activation.
已经开发出一种意想不到的无金属 C≡C 三键断裂、双氧活化和重新组装成色氨酸衍生物。这种化学反应提供了一种新颖、简单且有效的方法,可以在温和条件下从简单底物获得高价值的色氨酸衍生物。机理研究可能会通过 CC 键裂解和分子氧活化促进新方法的发现。
Practical selective monohydrolysis of bulky symmetric diesters
作者:Jianjun Shi、Satomi Niwayama
DOI:10.1016/j.tetlet.2017.12.061
日期:2018.2
has been applied to monohydrolysis of several bulkyl symmetric diesters, including diethyl esters, dipropyl esters, and dibutyl esters. A greater proportion of a polar aprotic co-solvent, DMSO, and aqueous KOH appear to help improve the reactivity of bulky diesters compared to the corresponding dimethylesters. The procedure is mild and practical, yielding the corresponding half-esters in high yields
Reaction between Dialkyl Acetylenedicarboxylates and Arylsulfonyl Isocyanates in the Presence of Trialkyl Phosphites: A Simple and Efficient Synthesis of Tetrasubstituted Hydantoins
作者:Abdolali Alizadeh、Hamid R. Bijanzadeh
DOI:10.1055/s-2004-834893
日期:——
This involves reaction of dialkyl acetylenedicarboxylates and arylsulfonylisocyanates in the presence of trialkyl phosphites. Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:2 addition reaction between trialkyl phosphites and dialkyl acetylenedicarboxylates in the presence of arylsulfonylisocyanates. These hydantoin-containing phosphoranes exist in solution as a
Dual C(sp<sup>3</sup>
)−H Bond Functionalization of N-Heterocycles through Sequential Visible-Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions
through a sequential visible‐light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid