Scalable methodologies for the synthesis of novel unsymmetrically-substituted secondary amines
作者:Gheorghe Roman
DOI:10.2298/jsc110408173r
日期:——
Fast, easy, and scalable methodologies for the synthesis of unsym- metrically substituted secondary amines containing naphthalene, indole, pyri- dine and imidazole moieties through reductive amination were explored. The investigated operating procedures were successful on a 50- to 30-mmol scale, and present a high potential for up-scaling.
Cationic chiral Au(I) complexes catalyze asymmetric Pictet-Spenglerreactions between tryptamines and arylaldehydes. The resulting tetrahydro-β-carbolines are obtained with wide functional group tolerance in high yield and with high enantioselectivities (up to 95%). Aldehydes bearing polar or protic functions are well tolerated. The reaction features a hitherto unknown C2-auration of the indole as
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
Herein, we report an unprecedented intramolecular cross-nucleophile coupling strategy of indole tethered β-amino acrylates using a catalyst system combining λ3-iodanes and Lewis acids to achieve the chemodivergent synthesis of three unique alkaloid skeletons. It was worth noting that the acquisition of spiroindolenines and azepino[4,5-b]indoles derivatives was switchable with choice of the Lewis acids
在此,我们报告了一种前所未有的吲哚系链β-氨基丙烯酸酯的分子内交叉亲核偶联策略,该策略使用结合λ 3 -碘烷和路易斯酸的催化剂体系来实现三种独特生物碱骨架的化学发散合成。值得注意的是,螺二氢吲哚和氮杂[4,5- b ]吲哚衍生物的获得可以通过路易斯酸的选择进行切换。此外,含有内酯片段的多环螺二氢吲哚也可以通过交叉亲核偶联级联分子内缩合序列首次获得。
Copper/Iodine Co-catalyzed Oxygenative Transannulation of Tryptamines Enables Direct Synthesis of Donaxaridine and Its Derivatives
transannulation strategy using readily available tryptamines. Molecular oxygen and water are used as oxygen sources and provide direct access to the donaxaridine scaffold and its derivatives. This methodology is applied to the efficient synthesis of the natural products donaxaridine, chimonamidine, donaxanine, donaxarine, and aline in just one or two steps. The tryptamines, albeit with oxy-sensitive dialkyl N-H