Scope and Mechanistic Studies of Catalytic Hydrosilylation with a High-Valent Nitridoruthenium(VI)
摘要:
Hydrosilylation catalyzed by a high-valent nitridonithenium(VI) compound, [RuN(saldach)(CH3OH)(+)[ClO4](-) (1, where saldach is the dianion of racemic N,N'-cyclohexan-diyl-bis(salicylideneimine)) is described. Using phenylsilane as reductant, a variety of unsaturated organic substrates, including aldehydes, ketones, and imines, are effectively reduced to alcohols and amines, respectively, accompanied by the redistribution of PhSiH3 at silicon. Mechanistic studies indicate that the catalysis proceeds via silane activation rather than carbonyl activation, and the silane is likely activated via multiple pathways, including a radical-based pathway.
Controlled and Chemoselective Reduction of Secondary Amides
作者:Guillaume Pelletier、William S. Bechara、André B. Charette
DOI:10.1021/ja105194s
日期:2010.9.22
presence of 2-fluoropyridine. The electrophilic activated amide can then be reduced to the corresponding iminium using triethylsilane, a cheap, rather inert, and commercially availablereagent. Imines can be isolated after a basic workup or readily transformed to the aldehydes following an acidic workup. The amine moiety can be accessed via a sequential reductive amination by the addition of silane and
Manganese‐Catalyzed Selective Hydrogenative Cross‐Coupling of Nitriles and Amines to Form Secondary Imines
作者:Xiao‐Gen Li、Qi‐Lin Zhou
DOI:10.1002/adsc.202100285
日期:2021.7.20
Manganese complexes with tridentate PNN ligands have been synthesized as catalysts for hydrogenative cross-coupling reaction of nitriles and amines to form secondary imines. This reaction afforded a variety of unsymmetrical secondary imines in good yields with excellent selectivity. Investigation of catalyst intermediates indicated that an amido manganese complex may be the active catalyst species
Gold‐Catalyzed Synthesis of 1,3‐Diaminopyrazoles from 1‐Alkynyltriazenes and Imines
作者:Loïc N. Jeanbourquin、Rosario Scopelliti、Farzaneh Fadaei Tirani、Kay Severin
DOI:10.1002/hlca.201700186
日期:2017.10
A new procedure for the synthesis of highly substituted 1,3‐diaminopyrazoles is described. As substrates, we have employed 1‐alkynyltriazenes and imines. The formation of pyrazoles was achieved by two‐fold C–N coupling reactions in the presence of (JohnPhos)AuCl and AgNTf2 as catalyst precursors. The regioselectivity of the reaction was inferred from a crystallographic analysis of one reaction product
作者:Merle Arrowsmith、Michael S. Hill、Gabriele Kociok-Köhn
DOI:10.1002/chem.201203190
日期:2013.2.18
The β‐diketiminato magnesium alkyl complex [LMgnBu] (L=CHCMe(NDipp)}2, Dipp=diisopropylphenyl) is shown to be a highly effective precatalyst for the hydroboration of alkyl and aryl substituted aldimines and ketimines with pinacol borane (HBpin). Catalysis is proposed to occur through a sequence of MgN/BH metathesis and rate‐determining MgH/NC insertion steps, a proposal strongly supported by stoichiometric
已显示β-二酮基亚氨基镁烷基络合物[LMg n Bu](L = CH CMe(NDipp)} 2,Dipp =二异丙基苯基)是高效的催化剂,用于频哪醇硼烷对烷基和芳基取代的亚胺和酮亚胺进行氢硼化(HBpin)。催化提出通过Mg的顺序发生 N / B ħ复分解和速度确定的Mg H /NC插入步骤,这一建议得到化学计量研究和动力学分析的大力支持。可以观察到反应是通过定义明确的酰胺酰胺进行的,其中有两个例子已被分离并进行了结构表征。机理研究表明,催化速率确定过程发生在一个孤立的镁中心,需要两个分子的亚胺底物才能有效转换。后者的观察结果被合理地认为是辅助底物分子将HBpin从催化镁中心的配位域置换出来的要求。
Titanium Induced Coupling of Imines to Symmetrical Vicinal (R*,R*)-Diamines
Symmetrical vicinal (R*,R*)-d,l-diamines were prepared from the corresponding imines and low valent titanium species generated by the action of titanium tetrachloride on amalgamated magnesium.