Brønsted Acid Enhanced Rhodium-Catalyzed Conjugate Addition of Aryl CH Bonds to α,β-Unsaturated Ketones under Mild Conditions

2012 ◽  
Vol 18 (31) ◽  
pp. 9511-9515 ◽  
Author(s):  
Lei Yang ◽  
Bo Qian ◽  
Hanmin Huang
2015 ◽  
Vol 44 (45) ◽  
pp. 19636-19641 ◽  
Author(s):  
Tao Luo ◽  
Rui Zhang ◽  
Xiao Shen ◽  
Wei Zhang ◽  
Chuanfa Ni ◽  
...  

An efficient 1,2-fluorine migration reaction was realized under Brønsted acid catalysis in the absence of an external fluorinating source. The high fluorine atom economy and very mild conditions make this reaction a promising protocol for the construction of the C–F bond.


2021 ◽  
Author(s):  
Ming-Jun Yi ◽  
Teng-Fei Xiao ◽  
Wen-Hui Li ◽  
Yi-Fan Zhang ◽  
Pen-Ji Yan ◽  
...  

A metal-free C(sp3)–H phosphorylation of saturated aza-heterocycles via the merger of organic photoredox and Brønsted acid catalysis was established under mild conditions. This protocol provided a straightforward and economic access...


2020 ◽  
Vol 56 (42) ◽  
pp. 5661-5664
Author(s):  
Yukihiro Arakawa ◽  
Tomohiro Mihara ◽  
Hiroki Fujii ◽  
Keiji Minagawa ◽  
Yasushi Imada

Visible light irradiation to flavins in the presence of thiols and O2 provides Brønsted acidic species that can be used as efficient catalysts for thioacetalizations and for Mannich-type reactions under non-irradiation and mild conditions.


2016 ◽  
Vol 14 (31) ◽  
pp. 7447-7450 ◽  
Author(s):  
Xiaoqian Yuan ◽  
Xinxin Wu ◽  
Shupeng Dong ◽  
Guibing Wu ◽  
Jinxing Ye

We report herein a highly efficient intramolecular coupling reaction of tertiary amines and ketones (α,β-unsaturated ketones) by using a Brønsted acid as a cocatalyst, affording 2-arylindols in good to excellent yields (up to 92%) under visible light irradiation at room temperature.


2013 ◽  
Vol 9 ◽  
pp. 1526-1532 ◽  
Author(s):  
Wantanee Sittiwong ◽  
Michael W Richardson ◽  
Charles E Schiaffo ◽  
Thomas J Fisher ◽  
Patrick H Dussault

Re(VII) oxides catalyze the acetalization, monoperoxyacetalization, monothioacetalization and allylation of hemiacetals. The reactions, which take place under mild conditions and at low catalyst loadings, can be conducted using hemiacetals, the corresponding O-silyl ethers, and, in some cases, the acetal dimers. Aldehydes react under similar conditions to furnish good yields of dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or a Brønsted acid.


Synlett ◽  
2020 ◽  
Vol 31 (08) ◽  
pp. 813-817
Author(s):  
Yoshihiro Nagao ◽  
Kou Hiroya

The synthesis of oxazolines using electrophilic cyclization of allylic amide is a simple and powerful method. However, cyclization involving arylsulfenylation requires harsh reaction conditions. We found that the reaction proceeds under mild heating conditions with the combination of a Brønsted acid and tetrabutylammonium chloride. This method enabled the synthesis of 5-[(arylsulfenyl)methyl]oxazoline derivatives under mild conditions and demonstrated high tolerance for various functional groups.


2018 ◽  
Author(s):  
Edward Richmond ◽  
Jing Yi ◽  
Vuk D. Vuković ◽  
Fatima Sajadi ◽  
Christopher Rowley ◽  
...  

<div><p>Ring-opening hydroarylation of cyclopropanes is typically limited to substrates bearing a donor-acceptor motif. Here, the transformation is achieved for monosubstituted cyclopropanes by using catalytic Brønsted acid in hexafluoroisopropanol (HFIP) solvent, constituting a rare example where such cyclopropanes engage in intermolecular C–C bond formation. Branched products are obtained when electron-rich arylcyclopropanes react with a broad scope of arene nucleophiles in accord with a simple S<sub>N</sub>1-type ring-opening mechanism. In constrast, linear products are obtained when cyclopropylketones react with electron-rich arene nucleophiles. In the latter case, mechanistic experiments and DFT-calculations support a homo-conjugate addition pathway.</p></div>


2021 ◽  
pp. 1-13
Author(s):  
Yasuhiro Matsumoto ◽  
Yuta Taguchi ◽  
Naruhiro Yoshida ◽  
Shugo Tokai ◽  
Tomoyuki Maruyama ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document