824-21-5Relevant articles and documents
Application of Mutualism in Organic Synthetic Chemistry: Mutually Promoted C?H Functionalization of Indole and Reduction of Quinoline
Zhang, Sutao,Xu, Hai,He, Jianghua,Zhang, Yuetao
supporting information, p. 5319 - 5329 (2021/09/29)
Here we reported a one-pot, metal-free B(C6F5)3-catalyzed strategy for simultaneous synthesis of C3-regioselective functionalization of indoles and complete reduction of quinolines. It turned out that by sharing a quinolinium hydridoborate intermediate, the original determining steps with high energy barrier in both the convergent disproportionation of indole and reduction of quinoline could be realized at room temperature, thus furnishing both the C3-borylated (or silylated) indoles and N-borylated tetrahydroquinolines in up to 98% yields at room temperature. Mechanistic studies suggested that both reactions would consume a product generated from the other reaction such that they can mutually promote each other, thus producing desirable products in a high atom-economy and low energy-cost manner. This strategy opened the gate to introducing mutualism to the field of chemistry. (Figure presented.).
B(C6F5)3-Catalyzed (Convergent) Disproportionation Reaction of Indoles
Han, Yuxi,Zhang, Sutao,He, Jianghua,Zhang, Yuetao
supporting information, p. 7399 - 7407 (2017/06/05)
A metal-free B(C6F5)3-catalyzed approach is developed for the disproportionation reaction of a series of indoles with various hydrosilanes, without any additives such as base and production of any small molecule such as dihydrogen. This boron catalyst system also exhibits excellent catalytic performance for practical application, such as catalyst loading as low as 0.01 mol % under solvent-free conditions, and a long-life catalytic performance highlighted by a constant catalytic activity being maintained and excellent yields being achieved for the desired products over 10 sequential additions of starting materials. On the basis of characterization of key intermediates through a series of in situ NMR reactions and detailed experimental data, we proposed a reaction mechanism which illustrated pathways for the formation of different products, including both major products and byproducts. Additional control experiments were conducted to support our proposed mechanism. Understanding the mechanism enables us to successfully suppress side reactions by choosing appropriate substrates and hydrosilanes. More importantly, the use of an elevated reaction temperature for continuous oxidation of the resulting indoline to indole makes the convergent disproportionation reaction an ideal atom-economical process. Near-quantitative conversions and up to 99% yields of C3-silylated indoles were achieved for various indoles with trisubstituted silanes, Ph3SiH (2b) or Ph2MeSiH (2d).
N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion of N-aziridinyl imines
Mahoney, Stuart J.,Fillion, Eric
, p. 68 - 71 (2012/02/04)
Under rhodium catalysis, N-aziridinyl imines provided access to N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion. The utility of this methodology for the synthesis of architecturally complex heterocycles was further demonstrated by an expedient total synthesis of ( ±)-cryptaustoline (see scheme). Copyright
