A Convenient Method for the Preparation of Secondary Propargylic Ethers. The Reactions of Acetals with 1-Trimethylsilyl-1-alkynes Promoted by the Combined Use of Catalytic Amounts of Tin(IV) Chloride and Zinc Chloride
SnCl4 and ZnCl2, acetals undergo a coupling with 1-trimethylsilylalkynes to give secondary propargylic ethers in good yields. Similarly, propargylic ethers are directly produced from aldehydes by the treatment with alkoxytrimethylsilanes and 1-trimethylsilylalkynes under the same conditions. This catalyst system also efficiently promotes aldol reaction of silylenolethers with acetals or aldehydes, and
A metal-free direct alkylation of CâH bonds adjacent to an oxygen or nitrogen atom was developed. This reaction occurred between saturated heterocycles and ethynylbenziodoxolones under mild conditions. A series of 2-alkynyl cyclic alkanes that contain oxygen or nitrogen atoms were prepared in moderate to good yields.
Practical and Highly Selective CH Functionalization of Structurally Diverse Ethers
作者:Miao Wan、Zhilin Meng、Hongxiang Lou、Lei Liu
DOI:10.1002/anie.201407083
日期:2014.12.8
A trityl ion mediated CHfunctionalization of ethers with a wide range of nucleophiles at ambient temperature has been developed. The reaction displays high chemoselectivity and good functional group tolerance. The protocol also exhibits excellent regio‐ and diastereoselectivities for the unsymmetric ethers, thus stereoselectively generating highlyfunctionalized disubstituted 2,5‐trans tetrahydrofurans
Synthesis of Dialkyl Ethers from Organotrifluoroborates and Acetals
作者:T. Andrew Mitchell、Jeffrey W. Bode
DOI:10.1021/ja906514s
日期:2009.12.23
The formation of ethers by C-O bond formation under harsh basic or acidic conditions is an entrenched synthetic disconnection in organic chemistry. We report a strategic alternative that involves the BF(3).OEt(2)-promoted coupling of stable, easily prepared acetals with widely available potassium aryl-, alkenyl-, and alkynyltrifluoroborates. This fast, operationally simple process offers straightforward
在苛刻的碱性或酸性条件下通过 CO 键形成形成醚是有机化学中根深蒂固的合成断开。我们报告了一种战略替代方案,涉及 BF(3).OEt(2) 促进的稳定、易于制备的缩醛与广泛可用的芳基-、烯基-和炔基三氟硼酸钾的偶联。这种快速、操作简单的过程提供了直接获得二烷基醚的途径,其中许多使用经典方法难以制备。使用 MOM 保护的醇和缩醛保护的醛可以形成醚,而无需求助于保护基操作或强碱。
Nucleophilic Substitution of Secondary Alkyl-Substituted Propargyl Acetates: An Economic and Practical Indium Trichloride Catalyzed Access
An economic and practical transformation from secondary alkyl-substituted propargyl acetates to a variety of nucleophilic substitution products was described. This reaction was catalyzed by inexpensive InCl3. High yields and excellent chemoselectivity were obtained. The five-, six-, and seven-membered propargyl cycloethers were also successfully constructed by this protocol.