Steric and electronic effects on the regioselective formation of platinum(II) metallacycles: crystal structure of [PtMe(3-MeC6H3CHNCH2C6H5)(PPh3)]
摘要:
The reaction of [Pt(2)Me(4)(mu-SMe(2))(2)] (1) with imines 3,4-(OMe)(2)C6H3CH=NCH(2)Ph (2c) and 3-MeC(6)H(6)CH=NCH(2)Ph (2e) yields cyclometallated compounds [PtMe(3,4-(OMe)(2)C6H2CH=NCH(2)Ph)(SMe(2))] (4c) and [PtMe(3-MeC(6)H(3)CH=NCH(2)Ph)(SMe(2))] (4e) arising from selective metallation at the less hindered of the two non-equivalent ortho positions of the aryl ring, followed by loss of methane. These compounds react with PPh(3) to give cyclometallated compounds [PtMe(3,4-(OMe)(2)C6H2CH=NCH(2)Ph)(PPh(3))] (5c) and [PtMe(3-MeC(6)H(3)CH=NC(2)Ph)(PPh(3))] (5e). Imines 2,4,6-(OMe)(3)C6H2CH=NCH(2)Ph (2a), 3,5-(OMe)(2)C6H3CH=NCH(2)Ph (2b) and 2,5-Me(2)C(6)H(3)CH=NCH(2)Ph (2d) coordinate to platinum through the nitrogen atom to yield compounds [PtMe(2)(ArCH=NCH(2)Ph)(SMe(2))] (3) but fail to produce cyclometallated compounds.
Application of Sequential Cu(I)/Pd(0)-Catalysis to Solution-Phase Parallel Synthesis of Combinatorial Libraries of Dihydroindeno[1,2-<i>c</i>]isoquinolines
作者:Sarvesh Kumar、Thomas O. Painter、Benoy K. Pal、Benjamin Neuenswander、Helena C. Malinakova
DOI:10.1021/co200027c
日期:2011.9.12
methodology is compatible with a wide-range of aliphatic linear, branched, and ester functionalized N-substituents. Unexpectedly, the formation of regioisomers featuring a 1,2,3-contiguous substitution pattern in the aromatic ring of the indene core was observed. Three distinct combinatorial libraries with a total of 111 of members were synthesized, and 80 highly substituted dihydroindenoisoquinolines structurally
Oxidative Radical Skeletal Rearrangement Induced by Molecular Oxygen: Synthesis of Quinazolinones
作者:Yi-Feng Wang、Feng-Lian Zhang、Shunsuke Chiba
DOI:10.1021/ol4011745
日期:2013.6.7
Oxidative skeletal rearrangement of 5-aryl-4,5-dihydro-1,2,4-oxadiazoles into quinazolinones is induced by molecularoxygen (under a dry air atmosphere) that likely proceeds via transient iminyl radical species. Concise syntheses of biologically active quinazolinone derivatives were demonstrated using the present strategy.
Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand as an auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol
作者:Xiaozhong Chen、Yao Ai、Peng Liu、Chenchen Yang、Jiazhi Yang、Feng Li
DOI:10.1016/j.jcat.2021.08.037
日期:2021.10
A Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand was designed, synthesized, and found to be a general and efficient auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol as both hydrogen source and methylating reagent. In the presence of [Cp*Ir(2,2′-CH2BiBzImH2)Cl][Cl], a range
Enantioselective Strecker reaction of aldimines using potassium cyanide catalyzed by a recyclable macrocyclic V(<scp>v</scp>) salen complex
作者:S. Saravanan、Noor-ul H. Khan、Ajay Jakhar、Amamudin Ansari、Rukhsana I. Kureshy、Sayed H. R. Abdi、Gaurav Kumar
DOI:10.1039/c5ra18914d
日期:——
macrocyclic salen ligand derived from 1R, 2R-(−) diaminocyclohexane with trigol bisaldehyde was synthesized and evaluated as an efficient catalyst (5 mol%) for asymmetric addition of potassiumcyanide and trimethylsilyl cyanide to various N-benzylimines at −20 °C. The dimeric chiral macrocyclic salen complex was found to be an efficient recyclable catalyst to give a high yield (91%) of α-aminonitrile and
合成了基于手性大环salen配体的手性二聚大环V(V)salen配合物,该配体衍生自1 R,2 R -(-)二氨基环己烷与三醇双醛,并被评价为有效的催化剂(5 mol%),用于钾的不对称加成氰化物和三甲基甲硅烷基氰化物在-20°C时生成各种N-苄基亚胺。发现二聚手性大环赛伦络合物是一种有效的可循环催化剂,在2-甲氧基取代的N的情况下,可提供高产率(91%)的α-氨基腈和高手性诱导(ee可达99%)-苄基亚胺在16小时内。该催化体系在有机和无机氰化物来源下均能很好地工作,并且在保持对映选择性的情况下将催化剂循环使用多达五个循环。基于NMR研究和动力学,提出了催化对映选择性斯特雷克反应的可能机理。
Synthesis of tetra-substituted imidazoles and 2-imidazolines by Ni(0)-catalyzed dehydrogenation of benzylic-type imines
作者:Adrian Tlahuext-Aca、Oscar Hernández-Fajardo、Alma Arévalo、Juventino J. García
DOI:10.1039/c4dt02313g
日期:——
performed to yield asymmetrical tetra-substituted imidazoles and 2-imidazolines. This was achieved with a single operational step while maintaining good selectivity and atom economy. The catalytic system shows low to moderate tolerance for fluoro-, trifluoromethyl-, methyl-, and methoxy-substituted benzylic-type imines. In addition, the substitution pattern at the N-heterocyclic products was easily