A Class of Chiral‐Bridged Biphenyl Monophosphine Ligands with Benzofuran Moiety and The Application in Diastereo‐ and Enantioselective Au(I)‐Catalyzed Cycloaddition
摘要:
A class of novel chiral‐bridged biphenyl monophosphine ligands with a benzofuran moiety (He‐phos) has been successfully synthesized and reported. These ligands exhibited good performance in the gold‐catalyzed enantioselective cycloaddition reaction of 2‐(1‐alkynyl)‐2‐en‐1‐ones with nitrones, resulting in the successful preparation of a series of polyaryl‐substituted heterocyclic compounds with high enantioselectivities (up to 99% yield, 98% ee). The wide substrate adaptability (53 examples) and mild reaction conditions demonstrate the practicability of He‐phos in this reaction.
Trimethylsilyl chloride promoted synthesis of α-branched amines by nucleophilic addition of organozinc halides to nitrones
作者:Ying Fu、Yanhua Liu、Yaojuan Chen、Helmut M. Hügel、Minzhu Wang、Danfeng Huang、Yulai Hu
DOI:10.1039/c2ob26202a
日期:——
general procedure for the nucleophilicaddition of organozinc halides with nitrones in the presence of trimethylsilyl chloride has been developed. Trimethylsilyl chloride was found to be both an indispensable reaction promoter and a ready hydroxylamine protective agent in these reactions. The produced O-(trimethylsilyl)hydroxylamines can be easily reduced into corresponding amines just by a zinc–copper
A gold(I)‐catalyzed asymmetric intermolecular tandem [3+3]‐cyclization reaction of 2‐(1‐alkynyl)‐2‐ alken‐1‐ones with nitrones has been developed by using Ming‐Phos as a chiral ligand. This method enables access to the stereodivergent synthesis of highly substituted furo[3,4‐d][1,2]oxazines in excellent efficiency and stereoselectivity (up to 99% yield, 99% ee, >20 : 1 dr).
通过使用Ming-Phos作为手性配体开发了金(I)催化的2-(1-炔基)-2-链烯-1-酮与硝酮的不对称分子间串联[3 + 3]环化反应。该方法能够以优异的效率和立体选择性(高达99%的收率,99%ee,> 20:1 dr)获得高度取代的呋喃[3,4- d ] [1,2]恶嗪的立体发散性合成。
A New Type of Chiral Sulfinamide Monophosphine Ligands: Stereodivergent Synthesis and Application in Enantioselective Gold(I)-Catalyzed Cycloaddition Reactions
A simple, newtype of chiralsulfinamidemonophosphines, the so‐called Ming‐Phos ligands, is reported; these ligands could be easily prepared from inexpensive and commercially available starting materials. The Ming‐Phos ligands performed well in the enantioselectivegold‐catalyzed cycloadditionreaction of 2‐(1‐alkynyl)‐alk‐2‐en‐1‐ones with nitrones. Both enantiomers of the products could be obtained
A highly enantioselective gold-catalyzed intermolecular [3 + 2] cycloaddition of N-allenamides with nitrones was realized by the application of Ming-Phos M6 as a chiral ligand. Both enantiomers of the cycloadducts with opposite configuration could be obtained in high yields with high regio- and enantioselectivity by the employment of either diastereomer of the chiral ligand. The acidic N—H bond (hydrogen