AbstractAn acyl moiety generated from α‐oxocarboxylic acids via decarboxylation undergoes a palladium‐catalyzed chemoselective insertion into organic cyanamides to afford N‐monosubstituted α‐ketoamides.magnified image
Polystyrene-bound diaryl selenoxide and telluroxide have been prepared, which behaved as mild oxidizingagents for thiols to disulfides, phosphines to phosphine oxides, hydroquinone and catechol to p- and o-benzoquinones, and thioketones to oxo compounds. The telluroxide completed these reactions in shorter periods or under milder conditions than the selenoxide. In addition, they effected novel solvent-dependent
Catalytic hydration of cyanamides with phosphinous acid-based ruthenium(<scp>ii</scp>) and osmium(<scp>ii</scp>) complexes: scope and mechanistic insights
phosphinous acid-based complexes [MCl2(η6-p-cymene)(PMe2OH)] (M = Ru (1), Os (2)) as catalysts. The reactions proceeded cleanly under mild conditions (40–70 °C), in the absence of any additive, employing low metal loadings (1 mol%) and water as the sole solvent. In almost all the cases, the osmiumcomplex 2 featured a superior reactivity in comparison to that of its ruthenium counterpart 1. In addition
通过使用水合相应的氰胺R 1 R 2 NC N成功地完成了多种脲R 1 R 2 NC(O)NH 2的合成(R 1和R 2 =烷基,芳基或H; 26个实例)的三价膦酸基配合物[的MC1 2(η 6 - p -cymene)(PME 2 OH)](M =茹(1),锇(2))作为催化剂。反应在温和的条件下(40-70°C)干净进行,没有任何添加剂,使用低金属负载量(1 mol%)和水作为唯一溶剂。在几乎所有情况下,complex配合物2的反应活性都比钌配合物1高。另外,对于两种催化剂,氰酰胺底物水合所观察到的反应速率明显快于涉及传统脂族和芳族腈的反应速率。计算研究使我们能够合理化所有这些趋势。因此,计算表明存在直接与碳原子相连的氮原子当与金属中心配位时,N键通过感应效应使腈碳电子减少,从而促进次膦酸配体的OH基团对该碳的分子内亲核攻击。另一方面,Os对Ru的较高反应性似乎与初始金属环上较低的环应
A Metal and Base-Free Chemoselective Primary Amination of Boronic Acids Using Cyanamidyl/Arylcyanamidyl Radical as Aminating Species: Synthesis and Mechanistic Studies by Density Functional Theory
作者:Nachiketa Chatterjee、Minhajul Arfeen、Prasad V. Bharatam、Avijit Goswami
DOI:10.1021/acs.joc.6b00671
日期:2016.6.17
base-free, chemoselective synthesis of aryl-, heteroaryl-, and alkyl primary amines from the corresponding boronic acids has been achieved at ambient temperature mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA) and N-bromosuccinimide (NBS) using cyanamidyl/arylcyanamidyl radicals as the aminating species. The primary amine compounds were initially obtained as their corresponding ammonium trifluoroacetate
The cobalt-catalyzed cross-coupling of organozinc bromides with N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) is described. The same cobalt catalyst, cobalt(II) bromide, was used for both the synthesis of the organozinc species and the cross-coupling reaction. However in this case, a catalytic amount of zinc dust is necessary in the second step to release the low-valent cobalt. Under these mild
A facile and general synthesis of various N-substituted cyanamides was accomplished by the Tiemann rearrangement of amidoximes with benzenesulfonyl chlorides (TsCl or o-NsCl) and DIPEA.