A silver‐mediated oxidative difluoromethylation of styrenes and vinyl trifluoroborates with TMSCF2H is reported for the first time. This method enables direct and facile access to CF2H‐alkenes from abundant alkenes with excellent functional‐group compatibility. Moreover, this Ag/TMSCF2H protocol could further enable a series of radical difluoromethylation reactions of a wide array of substrates, offering
Selective Gold-Catalysed Synthesis of Cyanamides and 1-Substituted 1<i>H</i>
-Tetrazol-5-Amines from Isocyanides
作者:Karel Škoch、Ivana Císařová、Petr Štěpnička
DOI:10.1002/chem.201803252
日期:2018.9.18
The newly discovered gold‐catalysed reaction of isocyanides with hydrazoic acid generated in situ from trimethylsilyl azide and methanol (or, alternatively, from NaN3/AcOH) produces either cyanamides or 1‐substituted 1H‐tetrazol‐5‐amines, depending on the amount of available HN3. The reaction proceeds selectively and in generally high yields of either product, thus providing a particularly convenient
Fluoroalkylation of Various Nucleophiles with Fluoroalkyl Sulfones through a Single Electron Transfer Process
作者:Pan Xiao、Chuanfa Ni、Wenjun Miao、Min Zhou、Jingyu Hu、Dingben Chen、Jinbo Hu
DOI:10.1021/acs.joc.9b00419
日期:2019.7.5
substitution of the phenylsulfonyl group. Mechanistic studies indicated that these reactions proceed through a unimolecular radical nucleophilic substitution (SRN1) mechanism. It is worthwhile noting that in the cases of O-nucleophiles (t-BuO– and PhO–), the addition of t-BuOK/PhCHO could significantly promote the reactions, due to the in situ formation of a highly reactive electron donor species through
Screw sense selective polymerization of achiral isocyanides catalyzed by optically active nickel(II) complexes
作者:Paul C. J. Kamer、Roeland J. M. Nolte、Wiendelt. Drenth
DOI:10.1021/ja00228a035
日期:1988.9
screw sense. Therefore, it should be possible to obtain opticallyactive polymers by using chiral catalysts. In the present paper we describe the synthesis of opticallyactivepoly (isocyanides) by using Ni(II) complexes of opticallyactive amines as catalysts.15 The prevailing screw sense of the polymers is derived from CD R N H 2 1 R N H C H O 2 R N +
各种非手性异氰化物与该催化剂的聚合产生光学活性聚合物,其对映体过量高达 83%。在质子酸、路易斯酸或 Ni(II) 盐作为催化剂存在下,异氰化物聚合生成聚(异氰化物),也称为聚(亚氨基亚甲基)或聚(碳酰亚胺酰基)。1,2 Ni(II) 盐是多功能催化剂,在我们看来,最适合我们的实验。聚(异氰化物)是方案 I n Ni(II) ( RN = C < ) 中的不寻常聚合物 „ 其主链的每个原子都带有侧链 .1,2 这一特征导致围绕单键的旋转受限连接主链碳原子。单键周围可能有两种构象,即。R 和 S 。所得聚合物将是具有P和M螺杆的非对映异构分子的混合物。这种混合物将包含过量的一种螺旋感。在大约 20 种不同的光学活性异氰化物 0.10" 12 中观察到了这一点。在另一个过程中,我们通过特异性抑制外消旋对的一个螺旋方向的生长来制备光学活性聚合物。5,13 最后,在一种情况下,光学活性聚合物活性聚
Free-Radical Triggered Ordered Domino Reaction: An Approach to C–C Bond Formation via Selective Functionalization of α-Hydroxyl-(sp<sup>3</sup>)C–H in Fluorinated Alcohols
作者:Zhengbao Xu、Zhaojia Hang、Zhong-Quan Liu
DOI:10.1021/acs.orglett.6b01946
日期:2016.9.16
free-radical mediated highly ordered radical addition/cyclization/(sp3)C–C(sp3) formation domino reaction is developed. Three new C–C bonds are formed one by one in a mixed system. Furthermore, it represents the first example of cascade C–C bond formation via selective functionalization of α-hydroxyl-C(sp3)–H in fluorinated alcohols.