584-07-6Relevant academic research and scientific papers
Palladium-Catalyzed Synthesis of Indolines from Aroyloxycarbamates through a Tandem Decarboxylative Amination/Heck/Annulation Reaction
Wang, Zheng,Li, Peihe,Fu, Hui,Dai, Qipu,Hu, Changwen
, p. 192 - 200 (2018/11/23)
A novel synthesis of functionalized indolines via a Pd-catalyzed tandem decarboxylative amination/Heck/annulation reaction has been developed. This process features operational simplicity, mild conditions, and the use of a readily available and environmentally friendly starting material, namely carboxylic acid. Furthermore, the reaction shows good functional group tolerance and chemical selectivity. (Figure presented.).
Pyrrolidines and Piperidines by Ligand-Enabled Aza-Heck Cyclizations and Cascades of N-(Pentafluorobenzoyloxy)carbamates
Hazelden, Ian R.,Carmona, Rafaela C.,Langer, Thomas,Pringle, Paul G.,Bower, John F.
supporting information, p. 5124 - 5128 (2018/03/26)
Ligand-enabled aza-Heck cyclizations and cascades of N-(pentafluorobenzoyloxy)carbamates are described. These studies encompass the first examples of efficient non-biased 6-exo aza-Heck cyclizations. The methodology provides direct and flexible access to carbamate protected pyrrolidines and piperidines.
Synthesis of indoles from aroyloxycarbamates with alkynes: Via decarboxylation/cyclization
Ma, Nuannuan,Li, Peihe,Wang, Zheng,Dai, Qipu,Hu, Changwen
supporting information, p. 2421 - 2426 (2018/04/12)
An efficient Pd-catalyzed decarboxylation/cyclization of aroyloxycarbamates to realize substituted indoles has been disclosed. Terminal alkynes as the coupling partners lead to site specific 2-substituted indoles through two pathways, while internal alkynes with aroyloxycarbamates can be transformed to 2,3-disubstituted indoles directly. This protocol is further demonstrated by the efficient synthesis of indoles as well as the success of employing inexpensive aryl acids as starting materials to construct C-N bonds by releasing CO2.
Regioselective Synthesis of 2-Vinylanilines Using O-aroyloxycarba-mates by Sequential Decarboxylation/Amination/Heck Reaction
Li, Peihe,Ma, Nuannuan,Li, Jikun,Wang, Zheng,Dai, Qipu,Hu, Changwen
, p. 8251 - 8257 (2017/08/14)
A new sequential approach for 2-vinylanilines utilizing aryl carboxylic acids as stable, inexpensive and widely available arylating reagents is described. Employing a Pd-POVs catalyst system, this protocol is not only overcoming the restriction barrier of decarboxylative coupling to ortho-substituted substrates, but also provides site-special to create new C(sp2)-N and C(sp2)-C(sp2) bonds. Mechanistic experiments suggest the cleavage of C(sp2)-COOH gives priority to C(sp2)-X bond in this reaction.
Palladium-Catalyzed Decarboxylative Synthesis of Arylamines
Dai, Qipu,Li, Peihe,Ma, Nuannuan,Hu, Changwen
supporting information, p. 5560 - 5563 (2016/11/17)
A novel approach has been developed for the synthesis of arylamines via the palladium-catalyzed intramolecular decarboxylative coupling (IDC) of aroyloxycarbamates, obtained in situ by reacting aryl carboxylic acids with hydroxycarbamates. The reaction offers facile access to structurally diverse arylamines with the site-specific formation of the C(sp2)-N bond under mild conditions.
Serendipitous discovery of α-hydroxyalkyl esters as β-lactamase substrates
Pelto, Ryan B.,Pratt
experimental part, p. 10496 - 10506 (2011/10/18)
O-(1-Carboxy-1-alkyloxycarbonyl) hydroxamates were found to spontaneously decarboxylate in aqueous neutral buffer to form O-(2-hydroxyalkylcarbonyl) hydroxamates. While the former molecules do not react rapidly with serine β-lactamases, the latter are quite good substrates of representative class A and C, but not D, enzymes, and particularly of a class C enzyme. The enzymes catalyze hydrolysis of these compounds to a mixture of the α-hydroxy acid and hydroxamate. Analogous compounds containing aryloxy leaving groups rather that hydroxamates are also substrates. Structure-activity experiments showed that the α-hydroxyl group was required for any substantial substrate activity. Although both d- and l-α-hydroxy acid derivatives were substrates, the former were preferred. The response of the class C activity to pH and to alternative nucleophiles (methanol and d-phenylalanine) suggested that the same active site functional groups participated in catalysis as for classical substrates. Molecular modeling was employed to explore how the α-hydroxy group might interact with the class C β-lactamase active site. Incorporation of the α-hydroxyalkyl moiety into novel inhibitors will be of considerable interest.
Design, synthesis, and evaluation of duocarmycin O-amino phenol prodrugs subject to tunable reductive activation
Lajiness, James P.,Robertson, William M.,Dunwiddie, Irene,Broward, Melinda A.,Vielhauer, George A.,Weir, Scott J.,Boger, Dale L.
experimental part, p. 7731 - 7738 (2011/02/24)
A series of N-acyl O-amino derivatives of seco-CBI-indole2 are reported and examined as prototypical members of a unique class of reductively activated (cleaved) prodrugs of the duocarmycin and CC-1065 family of antitumor agents. These prodrugs were designed to be potentially preferentially activated in hypoxic tumor environments which carry an intrinsically higher concentration of "reducing" nucleophiles (e.g., thiols) capable of activating such derivatives by nucleophilic cleavage of a weak N-O bond. A remarkable range of stabilities and a resulting direct correlation with in vitro/in vivo biological potencies was observed for these prodrugs, even enlisting subtle variations in the electronic and steric environment around the weak N-O bond. An in vivo evaluation of several of the prodrugs demonstrates that some approach the potency and exceed the efficacy of the free drug itself (CBI-indole 2), suggesting the prodrugs may offer an additional advantage related to a controlled or targeted release.
Syntheses of Diamino-dideoxylyxose Derivatives using Acylnitroso Dienophiles
Defoin, Albert,Fritz, Hans,Schmidlin, Christian,Streith, Jacques
, p. 554 - 569 (2007/10/02)
N-Acylnitroso derivatives 6 which were prepared by in-situ oxidation of the corresponding hydroxamic acids 5 reacted instantaneously and in high yields with dihydropyridine 4.The Diels-Alder adducts 8 were formed regiospecifically with the acylnitroso dienophiles 6a-c, whereas the dienophiles 6d-f gave mixtures of both regioisomers 7 and 8.These and some other results were best explained by the FMO theory.The Diels-Alder adducts 7 and 8 gave the corresponding 'anti'-cis-glycols when reacted with OsO4/N-methylmorpholine N-oxide.Hydrogenolysis of the N-O bond folloved by peracetylation led to the expected aminolyxose derivatives 14 and 16.A similar sequence, using 4 and the hydroxamic-acid derivative 18 of (+)-D-mandelic acid led, with a poor assymmetric induction, to a mixture of the expected optically active aminolyxose compounds 19A/19B.
