7390-67-2Relevant academic research and scientific papers
Gold-Catalyzed Carboamination of Allenes by Tertiary Amines Proceeding with Benzylic Group Migration
Milcendeau, Pierre,Gandon, Vincent,Guinchard, Xavier
supporting information, p. 2893 - 2902 (2021/04/13)
Tertiary amines bearing a benzyl-type group (CH2Ar) undergo Au(I)-catalyzed intramolecular addition to allenes. A formal 1,3-transfer of the CH2Ar group takes place during the cyclization. As demonstrated by both experimental and DFT studies, these unprecedented intramolecular carboaminations involve two consecutive [3,3] rearrangements via a dearomatized intermediate. Because of the poor stability of the enamine products, protocols were developed to convert them in situ to more stable polycyclic chiral compounds. (Figure presented.).
Site-Selective Carbonylative Synthesis of Structurally Diverse Lactams from Heterocyclic Amines with TFBen as the CO Source
Ying, Jun,Gao, Qian,Wu, Xiao-Feng
, p. 14297 - 14305 (2019/11/03)
A palladium-catalyzed site-selective C-H carbonylation of heterocyclic amines for the synthesis of lactam motifs has been developed. The reaction of 3-thiophene methylamines, 2-thiophene methylamines, and tryptamines with benzene-1,3,5-triyl triformate (TFBen) as the CO source provides a series of structurally diverse lactams in moderate to high yields with excellent regioselectivities.
Metal-Free Dearomatization: Direct Access to Spiroindol(en)ines in Batch and Continuous-Flow
Ranjan, Prabhat,Ojeda, Gerardo M.,Sharma, Upendra K.,Van der Eycken, Erik V.
supporting information, p. 2442 - 2446 (2019/01/29)
A metal-free, phosphine-catalyzed intramolecular “umpolung Michael addition” on alkynes to form spiroindol(en)ines is reported. This nucleophilic catalysis enables the formation of a wide scope of five- and six-membered spiroindol(en)ines in moderate to excellent yields in batch as well as under continuous-flow conditions. Triphenylphosphine-catalyzed nucleophilic activation of alkynes allows the exclusive formation of exo-product under mild reaction conditions.
Synthesis of Spiroindolenines via Regioselective Gold(I)-Catalyzed Cyclizations of N-Propargyl Tryptamines
Magné, Valentin,Marinetti, Angela,Gandon, Vincent,Voituriez, Arnaud,Guinchard, Xavier
supporting information, p. 4036 - 4042 (2017/11/30)
N-Propargyl tryptamines bearing N-substituents such as propargyl, allyl, alkyl or benzyl groups undergo regioselective gold-catalyzed cyclizations to the corresponding spiroindolenines, while it was previously shown that N-sulfonyl-N-propargyl tryptamines lead to achiral azepino[4,5-b]indoles. An asymmetric approach to these spiroindolenines is disclosed using chiral gold complexes, leading to enantiomeric ratios up to 84/16. The spiroindolenines could be late-stage functionalized using Huisgen cyclizations, palladium-catalyzed cross couplings or reductions. Computational studies show that the reaction evolves via different mechanistic pathways depending on the nature of the substituent at the amine. (Figure presented.).
A Synthesis of Alsmaphorazine B Demonstrates the Chemical Feasibility of a New Biogenetic Hypothesis
Hong, Allen Y.,Vanderwal, Christopher D.
, p. 7306 - 7309 (2015/06/30)
An N-oxide fragmentation/hydroxylamine oxidation/intramolecular 1,3-dipolar cycloaddition cascade efficiently converted an oxidized congener of akuammicine into the complex, hexacyclic architecture of the alsmaphorazine alkaloids. This dramatic structural change shows the chemical feasibility of our novel proposal for alsmaphorazine biogenesis. Critical to these endeavors was a marked improvement in our previously reported Zincke aldehyde cycloaddition approach to indole alkaloids, which permitted the gram-scale synthesis of akuammicine. The chemoselective oxidations of akuammicine leading up to the key rearrangement also generated several biogenetically related alkaloids of the alstolucine and alpneumine families.
Chiral acetylenic sulfoxide in enantioselective synthesis of yohimbine alkaloid
Lee, Albert W.M.,Chan,Mo
, p. 3001 - 3004 (2007/10/03)
Through Michael addition/acid induced cyclization of secondary amine to chiral acetylenic sulfoxide followed by Pummerer cyclization, an approach to the enantioselective syntheses of pentacyclic yohimbine alkaloids is presented.
