Oxidation during reductive cyclisations using Bu3SnH
作者:W.Russell Bowman、Harry Heaney、Benjamin M. Jordan
DOI:10.1016/s0040-4020(01)96061-2
日期:1991.1
Reductivecyclisations using Bu3SnH include an “oxidation” step if the removal of an acidic proton from the intermediate cyclised radical, by Bu3SnH acting as a base, is favourable. A “pseudo” SRN1 mechanism is proposed.
如果通过Bu 3 SnH作为碱从中间环化自由基中除去酸性质子是有利的,则使用Bu 3 SnH进行的还原环化包括一个“氧化”步骤。提出了一种“伪” S RN 1机制。
C–N Coupling of Amides with Alcohols Catalyzed by N-Heterocyclic Carbene–Phosphine Iridium Complexes
作者:Sutthichat Kerdphon、Xu Quan、Vijay Singh Parihar、Pher G. Andersson
DOI:10.1021/acs.joc.5b01324
日期:2015.11.20
N-Heterocycliccarbene–phosphineiridiumcomplexes (NHC–Ir) were developed/found to be a highly reactive catalyst for N-monoalkylation of amides with alcohols via hydrogen transfer. The reaction produced the desired product in high isolated yields using a wide range of substrates with low catalyst loading and short reaction times.
Ynamides are tested as new partners in radical and organometallic transformations. A radical cascade involving a 5-exo-dig cyclization followed by a 6-endo-trig radical trapping transforms ynamides into hetero-polycyclic compounds such as isoindoles, isoindolinones and pyrido-isoindolones. Various ene–tosylynamides react with platinum(II) chloride and lead to bicyclic nitrogenated heterocycles. This
induced by ultraviolet (UV) light. Forty-six examples with various functional groups are explored at room temperature with irradiation by three 26 W UV lamps (350–380 nm). The yield reaches 97%. The gram scale experiment product yield is 76%. Moreover, this system can be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under
Copper(I)-Catalyzed Reductive Cross-Coupling of<i>N</i>-Tosylhydrazones with Amides: A Straightforward Method for the Construction of C(<i>sp</i><sup>3</sup>)N Amide Bonds from Aldehydes
作者:Peng Xu、Fu-She Han、Yan-Hua Wang
DOI:10.1002/adsc.201500331
日期:2015.11.16
A method for the one-potsynthesis of substituted amidesfromaldehydes and amides is presented. Namely, condensation of aldehydes with N-tosylhydrazide generated the N-tosylhydrazones which were then reductively cross-coupled in situ with primary or secondary amides in the presence of a copper catalyst to afford secondary or tertiary amides, respectively. The reaction proceeded efficiently for a wide