Symmetry swap: A C2‐chiral spiro diphosphine oxide (SpinPO) has been found to be highly efficient and enantioselective in the catalysis of double‐aldol reactions of ketones and aldehydes to give the corresponding optically active double‐aldol products, which can be readily transformed into optically active C3‐ and pseudo‐C3‐symmetric molecules.
Protection of Hydroxyl Groups as a Trimethylsilyl Ether by 1,1,1,3,3,3-Hexamethyldisilazane Promoted by Aspartic Acid as an Efficient Organocatalyst
作者:Arash GHORBANI-CHOGHAMARANI、Masoomeh NOROUZI
DOI:10.1016/s1872-2067(10)60210-0
日期:2011.1
Abstract A wide variety of alcohols and phenols were protected as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyl disilazane catalyzed by aspartic acid as a non-toxic, metal-free, and green organocatalyst at room temperature in acetonitrile under mild and heterogeneous conditions. The procedure is operationally simple and the silylated product was obtained in high yield and purity.
Enantioselective Synthesis of Allenes by Catalytic Traceless Petasis Reactions
作者:Yao Jiang、Abdallah B. Diagne、Regan J. Thomson、Scott E. Schaus
DOI:10.1021/jacs.6b11937
日期:2017.2.8
Allenes are useful functional groups in synthesis as a result of their inherent chemical properties and established reactivity patterns. One property of chemical bonding renders 1,3-substituted allenes chiral, making them attractive targets for asymmetric synthesis. While there are many enantioselective methods to synthesize chiral allenes from chiral starting materials, fewer methods exist to directly
SYNTHESIS OF CHIRAL 2-METHYL-3-ALKENOIC ESTERS<i>VIA</i>1,2-REARRANGEMENT OF ALKENYL GROUP
作者:Yutaka Honda、Aiichiro Ori、Gen-ichi Tsuchihashi
DOI:10.1246/cl.1986.13
日期:1986.1.5
Hydrolysis of optically pure 1-alkenyl-2-sulfonyloxy-1-propanone acetals afforded optically and geometrically pure title compounds via stereospecific 1,2-rearrangement of alkenyl group.
Mass spectrometric studies of trimethylsilylpantothenic acid and related substances
作者:Michael Rychlik
DOI:10.1002/jms.157
日期:2001.5
characteristic fragment of trimethylsilylated pantothenic acid (TMS-PA) at m/z 291 upon electron ionization was shown to originate from the molecular ion by a McLaffertyrearrangement instead of by ejection of 1,1,3,3-tetramethyl-1,3-disilacyclobutane. The verification consisted of labelling experiments and high-resolution mass spectrometry of the fragment and studies on its isotopic distribution. The remaining
电子电离时,m / z 291处的三甲基甲硅烷基化的泛酸(TMS-PA)的特征片段显示是通过McLafferty重排而不是通过喷射1,1,3,3-四甲基-1,3源自分子离子的-二硅环丁烷。验证包括该片段的标记实验和高分辨率质谱分析及其同位素分布研究。通过B / E链接扫描和碰撞诱导的解离阐明了TMS-PA的其余碎裂途径。