Chemical Science, Год журнала: 2022, Номер 13(14), С. 4103 - 4108
Опубликована: Янв. 1, 2022
An asymmetric [1,2] Stevens rearrangement was realized via chiral guanidine and copper( i ) complexes. A series of novel dithioketal derivatives were obtained with good yields (up to 90% yield) enantioselectivities 96 : 4 er).
Язык: Английский
European Journal of Medicinal Chemistry, Год журнала: 2021, Номер 216, С. 113293 - 113293
Опубликована: Фев. 15, 2021
Язык: Английский
Процитировано
98
Accounts of Chemical Research, Год журнала: 2020, Номер 53(10), С. 2235 - 2247
Опубликована: Сен. 4, 2020
ConspectusTo improve the field of catalysis, there is a substantial and growing need for novel high-performance catalysts providing new reactivity. To date, however, set reactions that can be reliably performed to prepare chiral compounds in largely one enantiomeric form using still represents small fraction toolkit known transformations. In this context, Brønsted bases have played an expanding role catalyzing enantioselective between various carbon- heteroatom-centered acids host electrophilic reagents. This Account describes our recent efforts developing applying family incorporating H-bond donor moiety strongly basic iminophosphorane, which we named BIMPs (Bifunctional IMinoPhosphoranes), as efficient currently out reach more widespread tertiary amine centered bifunctional catalysts. The iminophosphorane base easily generated by Staudinger reaction organoazide commercially available phosphine, allows easy modification catalyst structure fine-tuning pKBH+. We demonstrated BIMP efficiently promote addition nitromethane low reactivity N-diphenylphosphinoyl (DPP)-protected imines ketones (ketimines) access valuable diamine α-quaternary amino acid building blocks, later extended methodology phosphite nucleophiles. Subsequently, scope was expanded include Michael high pKa alkyl thiols α-substituted acrylate esters, β-substituted α,β-unsaturated alkenyl benzimidazoles well challenging direct aldol aryl α-fluorinated ketones. Finally, were shown used key steps synthesis complex alkaloid natural products (−)-nakadomarin A (−)-himalensine A, polymer synthesis. most cases, predictable nature promoted multigram scale-up while employing loadings (down 0.05 mol%). Furthermore, it immobilized onto solid support one-step increased recycling flow chemistry applications. Alongside own work, also includes elegant work Johnson co-workers utilizing system, when alternative proved suboptimal.
Язык: Английский
Процитировано
96
Nature Communications, Год журнала: 2019, Номер 10(1)
Опубликована: Авг. 9, 2019
Abstract Organocatalysis is an important branch of catalysis for various organic transformations and materials preparation. Polymerizations promoted by catalysts can produce polymeric without any metallic residues, providing charming high-value sensitive domains such as biomedical applications, microelectronic devices food packaging. Herein, we describe a fluorinated alcohol based catalytic system polypeptide synthesis via ring-opening polymerization (ROP) α -amino acid N -carboxyanhydride (NCA), fulfilling cocatalyst free, metal high rate selectivity. During polymerization, the catalyst forms multiple dynamic hydrogen bonds with initiator, monomer propagating polymer chain. These cooperative bonding interactions activate NCA monomers simultaneously protect overactive initiator/propagating chain-ends, which offers whole activity Mechanistic studies indicate monocomponent-multifunctional mode alcohol. This finding provides free fast approach to access well-defined polypeptides.
Язык: Английский
Процитировано
90
Journal of the American Chemical Society, Год журнала: 2020, Номер 142(38), С. 16461 - 16470
Опубликована: Авг. 28, 2020
The defined structure of molecules bearing multiple stereogenic axes is increasing relevance to materials science, pharmaceuticals, and catalysis. However, catalytic enantioselective approaches control remain synthetically challenging. We report the synthesis two-axis terphenyl atropisomers, with complementary strategies both chlorinated brominated variants, formed high diastereo- enantioselectivity. chemistry proceeds through a sequence two distinct dynamic kinetic resolutions: first, an atroposelective ring opening Bringmann-type lactones produces product one established axis chirality, second, stereoselective arene halogenation delivers second chirality established. In order achieve these results, class Brønsted basic guanidinylated peptides, which catalyze efficient chlorination, reported for first time. addition, bromination reported, also establishes axis. These bromo-terphenyls are accessible following discovery that chiral anion phase transfer catalysis by C2-symmetric phosphoric acids allows catalyst in stereochemistry-determining event. Accordingly, we fully catalyst-controlled stereodivergent all possible stereoisomers while demonstrating diastereodivergence significant levels enantioselectivity cases.
Язык: Английский
Процитировано
80
ChemSusChem, Год журнала: 2021, Номер 14(14), С. 2785 - 2853
Опубликована: Май 13, 2021
Can green chemistry be the right reading key to let organocatalyst design take a step forward towards sustainable catalysis? What if intriguing promoted by more engineered organocatalysts was carried on using renewable and naturally occurring molecular scaffolds, or at least synthetic catalysts respectful principles of chemistry? Within frame these questions, this Review will tackle most commonly organic chiral from perspective their synthesis rather than employment in chemical methodologies processes. A classification catalyst scaffolds based E factor provided, global (E
Язык: Английский
Процитировано
78
Accounts of Chemical Research, Год журнала: 2021, Номер 54(15), С. 3108 - 3123
Опубликована: Июль 26, 2021
ConspectusOne of the constant challenges synthetic chemistry is molecular design and synthesis nonionic, metal-free superbases as chemically stable neutral organic compounds moderate weight, intrinsically high thermodynamic basicity, adaptable kinetic weak or tunable nucleophilicity at their nitrogen, phosphorus, carbon basicity centers. Such can catalyze numerous reactions, ranging from C–C bond formation to cycloadditions polymerization, name just a few. Additional benefits superbases, opposed inorganic counterparts, are solubility in reaction media, mild conditions, higher selectivity. Approaching such superbasic remains continuous challenge. However, recent advances methodology theoretical understanding have resulted new principles strategies toward superbases. Our computational contributions demonstrated that gas-phase region 350 kcal mol–1 even beyond easily reachable by organosuperbases. despite record-high basicities, physical limitations many these become quickly evident. The typically large weight molecules sensitivity ordinary conditions prevent them being practical, though preparation often not too difficult. Thus, obviously structural with respect complexity must be imposed on synthetically useful but for increasing remain important.The contemporary novel illustrated phosphazenyl phosphanes displaying basicities (GB) above 300 having weights well below 1000 g·mol–1. This approach based reconsideration phosphorus(III) compounds, which goes along stability solution. Another example carbodiphosphoranes incorporating pyrrolidine, tetramethylguanidine, hexamethylphosphazene substituent. With proton affinities up mol–1, they among top nonionic bases scale. Remarkably, achieved around 600 achieving through cooperative effect multiple intramolecular hydrogen bonding, increases stabilization conjugate acids, has recently been confirmed.This Account focuses our efforts produce embody desirable traits, other groups' approaches will also discussed. We reveal crucial features place known scales. discuss emerging potential current limits application give general outlook into future.
Язык: Английский
Процитировано
59
Applied Catalysis B Environment and Energy, Год журнала: 2021, Номер 291, С. 120099 - 120099
Опубликована: Март 5, 2021
Язык: Английский
Процитировано
58
Science China Chemistry, Год журнала: 2023, Номер 66(2), С. 526 - 533
Опубликована: Янв. 9, 2023
Язык: Английский
Процитировано
25
Journal of the American Chemical Society, Год журнала: 2024, Номер 146(5), С. 3065 - 3074
Опубликована: Янв. 28, 2024
Chiral 1-pyrrolines containing a nitrile motif serve as crucial structural scaffolds in biologically active molecules and exhibit diversity building blocks owing to their valuable functional groups; however, the asymmetric synthesis of such compounds remains largely unexplored. Herein, we present an enantio- diastereoselective method for α-chiral nitrile-containing 1-pyrroline derivatives bearing vicinal stereocenters through design introduction chiral cyclopropenimine-based bifunctional catalysts featuring thiourea moiety. This entails highly stereoselective conjugate addition α-iminonitriles wide array enones, followed by cyclocondensation, thereby affording series cyanopyrroline derivatives, some which contain all-carbon quaternary centers. Moreover, demonstrate synthetic utility this strategy performing gram-scale reaction with 1% catalyst loading, along variety chemoselective transformations product, including vildagliptin analogue. Finally, showcase selective all four stereoisomers products
Язык: Английский
Процитировано
12
Molecular Diversity, Год журнала: 2024, Номер unknown
Опубликована: Фев. 7, 2024
Язык: Английский
Процитировано
10