描述了在微波辐射条件下钯催化的二苯基二硫醚和二苯基二硒化物立体选择性加成到末端炔烃的三键的第一个例子。发现元素-元素(EE)和碳-元素键都可以在所研究的催化体系中被激活。两种反应的产物均以定量产率分离。根据量子化学计算,反应机制涉及 EE 键与 Pd0 的氧化加成。根据微波功率和反应条件,下一阶段是与炔烃的反应或碳元素键活化。Ph2Se2与Pd0氧化加成的产物,即双核络合物[Pd2(SePh)4(PPh32],
tris(dimethylamino)phosphine selenide, esters of selenophosphoric acid, and esters of selenophosphonic acid react with dihalogens and sulfurylchloride to form halogenoselenophosphonium salts (P–SeX)+X−. The latter undergo deselenization via ligand exchange to form phosphonium salts (P–X)+X− and elemental selenium. The stability of these salts depends on the substituents at the phosphorus atom and the type of counter
膦硒化物, 三(二甲氨基)膦硒化物, 酯类 的 硒磷酸, 和 酯类 的 硒代膦酸 与二卤素反应并 硫酰氯到形式halogenoselenophosphonium盐(P-性别)+ X - 。后者通过 配体交换形式鏻盐(P-X)+ X -和元素硒。这些盐的稳定性取决于磷原子上的取代基和抗衡离子的类型。salts盐可能与相应的equilibrium盐处于平衡状态磷烷,这证明了 酯类含有邻亚苯基配体。salts盐的结构,磷烷 和其他磷化合物的支持 31 P NMR光谱数据和电导率。其他证据来自卤代硒代phosph盐与环己烯。
Substituent Effects on <sup>31</sup>P NMR Chemical Shifts and <sup>1</sup>J<sub>P–Se</sub> of triarylselenophosphates
The effect of electron-withdrawing (EW) and electron-releasing (ER) substituents on the 31P NMR chemicalshifts and the structural parameters of a series of tris-(p-X-aryl)selenophosphates is reported in this article. Similarly to O-aryl phosphates and O-aryl thiophosphates, EW groups attached to aromatic rings induce a shielding effect on the 31P NMR signal. After a detailed experimental and theoretical
本文报道了吸电子 (EW) 和放电子 (ER) 取代基对 31 P NMR 化学位移和一系列三-(pX-芳基)硒代磷酸酯结构参数的影响。与 O-芳基磷酸酯和 O-芳基硫代磷酸酯类似,连接到芳环上的 EW 基团对 31P NMR 信号产生屏蔽效应。经过详细的实验和理论分析,我们证实硒原子是负责通过反向键合效应向磷转移电荷密度的主要部分。获得的完整系列的 1JP-Se 值与这一观察结果一致。补充材料可用于本文。转至出版商在线版的磷、硫和硅及相关元素,查看免费的补充文件。
Strecker; Grossmann, Chemische Berichte, 1916, vol. 49, p. 75
作者:Strecker、Grossmann
DOI:——
日期:——
Bicyclic Bridgehead Phosphoramidite (Briphos) Ligands with Tunable π-Acceptor Ability and Catalytic Activity in the Rhodium-Catalyzed Conjugate Additions
作者:Ansoo Lee、Seihwan Ahn、Kyungjun Kang、Min-Seob Seo、Yeonjoon Kim、Woo Youn Kim、Hyunwoo Kim
DOI:10.1021/ol502772m
日期:2014.10.17
A new type of bicyclic bridgehead phosphoramidites (briphos) is reported, where the geometrical constraints significantly enhance the pi-acceptor ability compared with its monocyclic analogs. The briphos is shown to be highly efficient and tunable for Rh(I)-catalyzed conjugate additions of aryl boronic acids to alpha,beta-unsaturated ketones and N-tosyl ketimines.