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Nature Chemistry Jan 2015The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical...
The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical research. Despite the centrality of amines in a number of important research areas, including medicinal chemistry, total synthesis and materials science, a general, selective and step-efficient synthesis of amines is still needed. Here, we describe a set of mild catalytic conditions utilizing a single copper-based catalyst that enables the direct preparation of three distinct and important amine classes (enamines, α-chiral branched alkylamines and linear alkylamines) from readily available alkyne starting materials with high levels of chemo-, regio- and stereoselectivity. This methodology was applied to the asymmetric synthesis of rivastigmine and the formal synthesis of several other pharmaceutical agents, including duloxetine, atomoxetine, fluoxetine and tolterodine.
Topics: Alkynes; Amination; Amines; Atomoxetine Hydrochloride; Benzhydryl Compounds; Catalysis; Copper; Cresols; Duloxetine Hydrochloride; Fluoxetine; Phenylpropanolamine; Propylamines; Stereoisomerism; Thiophenes; Tolterodine Tartrate
PubMed: 25515888
DOI: 10.1038/nchem.2131 -
Journal of the American Chemical Society Jan 2018Copper-catalyzed intermolecular carboamination of alkenes with α-halocarbonyls and amines is presented with 42 examples. Electron rich, electron poor, and internal...
Copper-catalyzed intermolecular carboamination of alkenes with α-halocarbonyls and amines is presented with 42 examples. Electron rich, electron poor, and internal styrenes, as well as α-olefins, are functionalized with α-halocarbonyls and aryl or aliphatic amines. Mechanistic investigations suggest the reaction is proceeding through addition of a carbon-centered radical across an olefin followed by oxidation to form a 5-membered oxocarbenium intermediate and subsequent nucleophilic ring opening to forge the C-N bond.
Topics: Alkenes; Amination; Amines; Catalysis; Copper; Molecular Structure
PubMed: 29095598
DOI: 10.1021/jacs.7b10529 -
Journal of the American Chemical Society Jan 2019A Rh-catalyzed enantioselective hydroamination of allylamines using a chiral BIPHEP-type ligand is reported. Enantioenriched 1,2-diamines are formed in good yields and...
A Rh-catalyzed enantioselective hydroamination of allylamines using a chiral BIPHEP-type ligand is reported. Enantioenriched 1,2-diamines are formed in good yields and with excellent enantioselectivities. A diverse array of nucleophiles and amine directing groups are demonstrated, including deprotectable motifs. Finally, the methodology was demonstrated toward the rapid synthesis of 2-methyl-moclobemide.
Topics: Allyl Compounds; Amination; Amines; Catalysis; Coordination Complexes; Ligands; Moclobemide; Rhodium; Stereoisomerism
PubMed: 30614700
DOI: 10.1021/jacs.8b09811 -
Organic Letters Jul 2022The first example of an aromatic haloform reaction is reported, defining a conceptually new haloform-type approach to the metal-free functionalization of arenes. We...
The first example of an aromatic haloform reaction is reported, defining a conceptually new haloform-type approach to the metal-free functionalization of arenes. We demonstrated that heteroarenes bearing a vinylogous nitromethane system, via the stage of a trichloromethane derivative, could undergo aromatic amination to produce N-functionalized arenes in quantitative yields and without the need for transition-metal catalysis. The haloform-type amination was implemented in the development of effective orthogonal N-protection strategies, establishing a new promising N-protecting reagent.
Topics: Amination; Catalysis
PubMed: 35763040
DOI: 10.1021/acs.orglett.2c01494 -
Molecules (Basel, Switzerland) Nov 2021The 3-hydroxy-1,5-dihydro-2-pyrrol-2-one motif is a valuable scaffold in drug discovery. The replacement of the 3-oxy fragment in...
The 3-hydroxy-1,5-dihydro-2-pyrrol-2-one motif is a valuable scaffold in drug discovery. The replacement of the 3-oxy fragment in 3-hydroxy-1,5-dihydro-2-pyrrol-2-ones-based compounds with a 3-amino one (3-amino analogs of 3-hydroxy-1,5-dihydro-2-pyrrol-2-ones, 3-amino-1,5-dihydro-2-pyrrol-2-ones) can play a crucial role in their biological effect. Thus, approaches to 3-amino-1,5-dihydro-2-pyrrol-2-ones are of significant interest. We developed an approach to 5-spiro-substituted 3-amino-1,5-dihydro-2-pyrrol-2-ones that could not be obtained using previously reported approaches (reactions of 3-hydroxy-1,5-dihydro-2-pyrrol-2-ones with amines). The developed approach is based on the thermal decomposition of 1,3-disubstituted urea derivatives of 5-spiro-substituted 3-hydroxy-1,5-dihydro-2-pyrrol-2-ones, which were prepared their reaction with carbodiimides.
Topics: Amination; Amines; Carbodiimides; Drug Discovery; Molecular Structure; Pyrroles
PubMed: 34885757
DOI: 10.3390/molecules26237179 -
Science (New York, N.Y.) Apr 2022Intermolecular cross-coupling of terminal olefins with secondary amines to form complex tertiary amines-a common motif in pharmaceuticals-remains a major challenge in...
Intermolecular cross-coupling of terminal olefins with secondary amines to form complex tertiary amines-a common motif in pharmaceuticals-remains a major challenge in chemical synthesis. Basic amine nucleophiles in nondirected, electrophilic metal-catalyzed aminations tend to bind to and thereby inhibit metal catalysts. We reasoned that an autoregulatory mechanism coupling the release of amine nucleophiles with catalyst turnover could enable functionalization without inhibiting metal-mediated heterolytic carbon-hydrogen cleavage. Here, we report a palladium(II)-catalyzed allylic carbon-hydrogen amination cross-coupling using this strategy, featuring 48 cyclic and acyclic secondary amines (10 pharmaceutically relevant cores) and 34 terminal olefins (bearing electrophilic functionality) to furnish 81 tertiary allylic amines, including 12 drug compounds and 10 complex drug derivatives, with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 :).
Topics: Alkenes; Amination; Amines; Carbon; Catalysis; Hydrogen; Palladium
PubMed: 35420962
DOI: 10.1126/science.abn8382 -
Chemical Reviews May 2022The chemistry of nitrogen-centered radicals (NCRs) has plentiful applications in organic synthesis, and they continue to expand as our understanding of these reactive... (Review)
Review
The chemistry of nitrogen-centered radicals (NCRs) has plentiful applications in organic synthesis, and they continue to expand as our understanding of these reactive species increases. The utility of these reactive intermediates is demonstrated in the recent advances in C-H amination and the (di)amination of alkenes. Synthesis of previously challenging structures can be achieved by efficient functionalization of sp moieties without prefunctionalization, allowing for faster and more streamlined synthesis. This Review addresses the generation, reactivity, and application of NCRs, including, but not limited to, iminyl, aminyl, amidyl, and aminium species. Contributions from early discovery up to the most recent examples have been highlighted, covering radical initiation, thermolysis, photolysis, and, more recently, photoredox catalysis. Radical-mediated intermolecular amination of (hetero)arenes can occur with a variety of complex amine precursors, generating aniline derivatives, an important class of structures for drug discovery and development. Functionalization of olefins is achievable in high anti-Markovnikov regioselectivity and allows access to difunctionalized structures when the intermediate carbon radicals are trapped. Additionally, the reactivity of NCRs can be harnessed for the rapid construction of N-heterocycles such as pyrrolidines, phenanthridines, quinoxalines, and quinazolinones.
Topics: Alkenes; Amination; Amines; Catalysis; Nitrogen
PubMed: 35285636
DOI: 10.1021/acs.chemrev.1c00831 -
Journal of the American Chemical Society Apr 2019C-N cross-coupling is one of the most valuable and widespread transformations in organic synthesis. Largely dominated by Pd- and Cu-based catalytic systems, it has...
C-N cross-coupling is one of the most valuable and widespread transformations in organic synthesis. Largely dominated by Pd- and Cu-based catalytic systems, it has proven to be a staple transformation for those in both academia and industry. The current study presents the development and mechanistic understanding of an electrochemically driven, Ni-catalyzed method for achieving this reaction of high strategic importance. Through a series of electrochemical, computational, kinetic, and empirical experiments, the key mechanistic features of this reaction have been unraveled, leading to a second generation set of conditions that is applicable to a broad range of aryl halides and amine nucleophiles including complex examples on oligopeptides, medicinally relevant heterocycles, natural products, and sugars. Full disclosure of the current limitations and procedures for both batch and flow scale-ups (100 g) are also described.
Topics: Amination; Amines; Catalysis; Density Functional Theory; Electrochemical Techniques; Kinetics; Molecular Structure
PubMed: 30905151
DOI: 10.1021/jacs.9b01886 -
Molecules (Basel, Switzerland) Jun 2023The construction of duocarmycin-like compounds is often associated with lengthy synthetic routes. Presented herein is the development of a short and convenient synthesis...
The construction of duocarmycin-like compounds is often associated with lengthy synthetic routes. Presented herein is the development of a short and convenient synthesis of a type of duocarmycin prodrug. The 1,2,3,6-tetrahydropyrrolo[3,2-]indole-containing core is here constructed from commercially available Boc-5-bromoindole in four steps and 23% overall yield, utilizing a Buchwald-Hartwig amination followed by a sodium hydride-induced regioselective bromination. In addition, protocols for selective mono- and di-halogenations of positions 3 and 4 were also developed, which could be useful for further exploration of this scaffold.
Topics: Duocarmycins; Prodrugs; Amination
PubMed: 37375372
DOI: 10.3390/molecules28124818 -
Journal of the American Chemical Society Jun 2022The direct functionalization of Si-H bonds by the nitrene insertion methodology is described. A copper(I) complex bearing a trispyrazolylborate ligand catalyzes the...
The direct functionalization of Si-H bonds by the nitrene insertion methodology is described. A copper(I) complex bearing a trispyrazolylborate ligand catalyzes the transfer of a nitrene group from PhI═NTs to the Si-H bond of silanes, disilanes, and siloxanes, leading to the exclusive formation of Si-NH moieties in the first example of this transformation. The process tolerates other functionalities in the substrate such as several C-H bonds and alkyne and alkene moieties directly bonded to the silicon center. Density functional theory (DFT) calculations provide a mechanistic interpretation consisting of a Si-H homolytic cleavage and subsequent rebound to the Si-centered radical.
Topics: Amination; Catalysis; Imines; Silanes
PubMed: 35648453
DOI: 10.1021/jacs.2c03739