876337-57-4Relevant academic research and scientific papers
NaClO-Promoted Atroposelective Couplings of 3-Substituted Indoles with Amino Acid Derivatives
Li, Zhaojie,Zhang, Hao,Yu, Shouyun
, p. 4754 - 4758 (2019)
A new class of C-N axial chirality based on N-indole sulfonamides has been disclosed. This new axially chiral N-indole sulfonamides were constructed by NaClO-promoted couplings of 3-substituted indoles with chiral amino acid-based sulfonamides. A series of structurally diverse N-indole sulfonamide-based atropisomers were prepared using this established method. The stability of these structurally interesting atropisomers highly relied on the C3-substituents of indoles and side chains of amino acid derivatives.
Iron-Catalyzed Reductive Cyclization by Hydromagnesiation: A Modular Strategy Towards N-Heterocycles
Larin, Egor M.,Lautens, Mark,Loup, Joachim
, p. 22345 - 22351 (2021/09/09)
A reductive cyclization to prepare a variety of N-heterocycles, through the use of ortho-vinylanilides, is reported. The reaction is catalyzed by an inexpensive and bench-stable iron complex and generally occurs at ambient temperature. The transformation likely proceeds through hydromagnesiation of the vinyl group, and trapping of the in situ generated benzylic anion by an intramolecular electrophile to form the heterocycle. This iron-catalyzed strategy was shown to be broadly applicable and was utilized in the synthesis of substituted indoles, oxindoles and tetrahydrobenzoazepinoindolone derivatives. Mechanistic studies indicated that the reversibility of the hydride transfer step depends on the reactivity of the tethered electrophile. The synthetic utility of our approach was further demonstrated by the formal synthesis of a reported bioactive compound and a family of natural products.
B(C6F5)3-Catalyzed Direct C3 Alkylation of Indoles and Oxindoles
Basak, Shyam,Alvarez-Montoya, Ana,Winfrey, Laura,Melen, Rebecca L.,Morrill, Louis C.,Pulis, Alexander P.
, p. 4835 - 4840 (2020/04/22)
The direct C3 alkylation of indoles and oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C-H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed this borane-catalyzed strategy in an alkylation-ring opening cascade.
Palladium-catalyzed enantioselective α-arylation and α-vinylation of oxindoles facilitated by an axially chiral p-stereogenic ligand
Taylor, Alexander M.,Altman, Ryan A.,Buchwald, Stephen L.
supporting information; experimental part, p. 9900 - 9901 (2009/12/06)
(Chemical Equation Presented) The enantioselective α-arylation and α-vinylation of oxindoles catalyzed by Pd and a biarylmonophosphine ligand with both axial and phosphorus-based chirogenicity is reported. The resultant quaternary carbon stereocenters are
Enantioselective TADMAP-catalyzed carboxyl migration reactions for the synthesis of stereogenic quaternary carbon
Shaw, Scott A.,Aleman, Pedro,Christy, Justin,Kampf, Jeff W.,Va, Porino,Vedejs, Edwin
, p. 925 - 934 (2007/10/03)
The chiral, nucleophilic catalyst TADMAP [1, 3-(2,2,2-triphenyl-1- acetoxyethyl)-4-(dimethylamino)-pyridine] has been prepared from 3-lithio-4-(dimethylamino)pyridine (5) and triphenylacetaldehyde (3), followed by acylation and resolution. TADMAP catalyzes the carboxyl migration of oxazolyl, furanyl, and benzofuranyl enol carbonates with good to excellent levels of enantioselection. The oxazole reactions are especially efficient and are used to prepare chiral lactams (23) and lactones (30) containing a quaternary asymmetric carbon. TADMAP-catalyzed carboxyl migrations in the indole series are relatively slow and proceed with inconsistent enantioselectivity. Modeling studies (B3LYP/6-31G*) have been used in qualitative correlations of catalyst conformation, reactivity, and enantioselectivity.
