Zn- and Cu-Catalyzed Coupling of Tertiary Alkyl Bromides and Oxalates to Forge Challenging C–O, C–S, and C–N Bonds
作者:Yuxin Gong、Zhaodong Zhu、Qun Qian、Weiqi Tong、Hegui Gong
DOI:10.1021/acs.orglett.0c04206
日期:2021.2.5
We describe here the facile construction of sterically hindered tertiary alkyl ethers and thioethers via the Zn(OTf)2-catalyzed coupling of alcohols/phenols with unactivated tertiary alkyl bromides and the Cu(OTf)2-catalyzed thiolation of unactivated tertiary alkyloxalates with thiols. The present protocol represents one of the most effective unactivated tertiary C(sp3)–heteroatom bond-forming conditions
Cu-Catalyzed Carbonylative Silylation of Alkyl Halides: Efficient Access to Acylsilanes
作者:Li-Jie Cheng、Neal P. Mankad
DOI:10.1021/jacs.9b12043
日期:2020.1.8
A Cu-catalyzed carbonylative silylation of unactivated alkyl halides has been developed, enabling efficient synthesis of alkyl-substituted acylsilanes in high yield. A variety of functional groups are tolerated under the mild reaction conditions, and primary, secondary and tertiaryalkyl halides are all applicable. The practical utility of this method has been demonstrated in the synthesis of acylsilanes
已开发出未活化的烷基卤化物的 Cu 催化羰基化硅烷化,能够以高产率高效合成烷基取代的酰基硅烷。在温和的反应条件下可耐受多种官能团,伯、仲、叔烷基卤均适用。该方法的实际效用已在带有不同甲硅烷基的酰基硅烷的合成中以及在一锅中将产物原位还原为相应的-羟基硅烷中得到证明。机理实验表明,甲硅烷基铜中间体通过单电子转移激活烷基卤化物以形成烷基自由基中间体,并且碳 - 卤素键断裂不参与速率决定步骤。
Direct halogenation of alcohols with halosilanes under catalyst- and organic solvent-free reaction conditions
作者:Njomza Ajvazi、Stojan Stavber
DOI:10.1016/j.tetlet.2016.04.083
日期:2016.6
A chemoselective method for the direct halogenation of different types of alcohols with halosilanes under catalyst- and solvent-freereactionconditions (SFRC) is reported. Various primary, secondary and tertiary benzyl alcohols and tertiary alkyl alcohols were directly transformed to the corresponding benzyl and alkyl halides, respectively, using chlorotrimethylsilane (TMSCl) and bromotrimethylsilane
α-cumyl(1-methyl-1-phenylethyl) cation suggested that π-delocalization in the phenonium ion is essentially less effective than through a benzylic π-interaction. On the other hand, the ρ value of −12.6 is distinctly larger than that for the ordinary benzylic carbocation systems, but is comparable to that of the benzenium ion. In addition, it has been found that the r+ value of the phenonium ions in the gas phase
<i>Z</i>-Selective Olefin Synthesis via Iron-Catalyzed Reductive Coupling of Alkyl Halides with Terminal Arylalkynes
作者:Chi Wai Cheung、Fedor E. Zhurkin、Xile Hu
DOI:10.1021/jacs.5b01784
日期:2015.4.22
Selective catalytic synthesis of Z-olefins has been challenging. Here we describe a method to produce 1,2-disubstituted olefins in high Z selectivity via reductive cross-coupling of alkylhalides with terminal arylalkynes. The method employs inexpensive and nontoxic catalyst (iron(II) bromide) and reductant (zinc). The substrate scope encompasses primary, secondary, and tertiaryalkylhalides, and