Article
Chemistry, Organic
Wei Liu, Donglei Wang, Dekun Zhang, Xiaoyu Yang
Summary: Optically active amines are crucial in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. The development of nonenzymatic asymmetric catalytic approaches for the kinetic resolution and desymmetrization of amines in the past two decades has been systematically summarized.
Article
Chemistry, Multidisciplinary
Benjamin Poelloth, Mukund P. Sibi, Hendrik Zipse
Summary: The factors responsible for the kinetic resolution of alcohols by chiral pyridine derivatives have been elucidated through accurate competitive linear regression analysis. Increasing the size of the aromatic side chain accelerates the reaction rate of the major enantiomer, leading to the design of a new catalyst with increased steric bulk for higher enantioselectivity values. Experimental and theoretical results suggest that the enhancement of enantioselectivity is achieved by accelerating the transformation of the major enantiomer through attractive non-covalent interactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Multidisciplinary Sciences
Ayumi Imayoshi, Bhatraju Vasantha Lakshmi, Yoshihiro Ueda, Tomoyuki Yoshimura, Aki Matayoshi, Takumi Furuta, Takeo Kawabata
Summary: Since the discovery of mechanically planar chiral rotaxanes and topologically chiral catenanes, their asymmetric synthesis has been a long-standing challenge. Here, the authors report enantioselective preparation of mechanically planar chiral rotaxanes with up to 99.9% ee in 29% yield.
NATURE COMMUNICATIONS
(2021)
Review
Chemistry, Organic
Wei Liu, Xiaoyu Yang
Summary: Chiral phosphoric acids have been recognized as one of the most powerful chiral organocatalysts and have been extensively applied in kinetic resolution, dynamic kinetic resolution and desymmetrization reactions, leading to significant developments in these areas since 2016.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Min Zhu, Martin Oestreich
Summary: A group-selective monosilylation of silanediols using List's counteranion-directed silylation methodology is described. The enantioselectivity is achieved by generating a silylium-ion-like silicon electrophile from an allylic silane paired with an imidodiphosphorimidate (IDPi), enabling discrimination of the two hydroxy groups attached to the prochiral silicon atom. Furthermore, the enantioselectivity is improved by a subsequent kinetic resolution, resulting in silicon-stereogenic disiloxanes with high enantiocontrol.
Article
Chemistry, Multidisciplinary
Biki Ghosh, Reena Balhara, Garima Jindal, Santanu Mukherjee
Summary: The first catalytic enantioselective Fischer indolization of prochiral diketones containing enantiotopic carbonyl groups is developed through dynamic kinetic resolution. Catalyzed by a combination of a spirocyclic chiral phosphoric acid and ZnCl2, this approach efficiently synthesizes cyclopenta[b]indole derivatives with an all-carbon quaternary stereocenter in good to excellent enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Organic
Helene Pellissier
Summary: Organocatalytic dynamic kinetic resolution (DKR) has emerged as a promising field in the past two decades, allowing efficient separation of chiral compounds. This review aims to provide an update on organocatalytic DKRs since 2016.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jian Song, Wen-Hua Zheng
Summary: A highly enantioselective method for the kinetic resolution of racemic tertiary alcohols has been developed using chiral organotin-catalyzed intermolecular acylation. The process can be carried out under mild reaction conditions and has a broad substrate scope, allowing for the separation of the corresponding products and highly enantioselective recovery of tertiary alcohols with s factors up to >200.
Article
Chemistry, Multidisciplinary
Jose A. Carmona, Patricia Rodriguez-Salamanca, Rosario Fernandez, Jose M. Lassaletta, Valentin Hornillos
Summary: An atroposelective Ir-catalyzed dynamic kinetic resolution (DKR) of 2-(quinolin-8-yl)benzaldehydes/1-naphthaldehydes is achieved by transfer hydrogenative coupling of allyl acetate. The reaction leads to the installation of central and axial chirality, with high diastereoselectivities and excellent enantioselectivities when ortho-cyclometalated iridium-DM-BINAP is used as the catalyst. The racemization of the substrates is facilitated through a designed transient Lewis acid-base interaction between the quinoline nitrogen atom and the aldehyde carbonyl group.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Yongkai Pan, Donglei Wang, Yunrong Chen, DeKun Zhang, Wei Liu, Xiaoyu Yang
Summary: The kinetic resolution of alpha-tertiary propargylic amines was successfully achieved through asymmetric remote aminations of anilines with azodicarboxylates enabled by chiral phosphoric acid catalysis. A broad range of substituents at the alpha-position were well tolerated, with high kinetic resolution performances. Additionally, excellent stereoselectivity was demonstrated for alpha-tertiary amines bearing an alpha-CN group under the same reaction conditions. The successful transformations of the chiral amination products and the recovered propargylic amines showcased the power of this method in asymmetric synthesis of alpha-tertiary amines and their derivatives.
Review
Chemistry, Organic
Tianyu Peng, Shixin Li, Dongxu Yang, Linqing Wang
Summary: Kinetic resolution is a practical method that selectively recovers enantiomerically pure starting materials and products from racemic mixtures. In this review, the less explored intramolecular kinetic resolution is discussed, highlighting its importance and elegance in generating chiral scaffolds. Different reaction types, including cyclization, elimination, isomerization, rearrangement, and miscellaneous reactions, are systematically presented and analyzed.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Masamichi Ogasawara
Summary: Planar-chiral transition metal complexes are important in asymmetric synthesis, but their preparation remains challenging. Reported examples of catalytic enantioselective synthesis of planar-chiral complexes are rare and represent a developing area in this field.
Article
Chemistry, Organic
Takeshi Yamamoto, Michinori Suginome, Ryo Murakami
Summary: PQXdpap exhibits different helical chirality switching under different solvent conditions and can effectively prepare enantiomerically pure alcohol compounds.
Article
Chemistry, Organic
Ken Okuno, Yasuaki Furuya, Seiji Shirakawa
Summary: The kinetic resolution of racemic compounds is a reliable method to prepare chiral molecules in highly optically enriched forms. However, the kinetic resolution of racemic carboxylic acids has not been well developed. Esterification and lactonization promoted by chiral organocatalysts have been found to be effective methods for the kinetic resolution of chiral carboxylic acids.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xing Yang, Pankaj Kumar Majhi, Huifang Chai, Bin Liu, Jun Sun, Ting Liu, Yonggui Liu, Liejin Zhou, Jun Xu, Jiawei Liu, Dongdong Wang, Yanli Zhao, Zhichao Jin, Yonggui Robin Chi
Summary: This research introduces a novel catalytic strategy to modulate the thermodynamics and control the enantioselectivities of asymmetric aldol reactions via post-aldol processes. By using an NHC catalyst to activate a masked enolate substrate, the study successfully achieves enantioselective acylative kinetic resolution, resulting in acylated aldol products with high optical purities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Weijie Chen, Anirudra Paul, Khalil A. Abboud, Daniel Seidel
Article
Chemistry, Multidisciplinary
Anirudra Paul, Jae Hyun Kim, Scott D. Daniel, Daniel Seidel
Summary: Despite efforts by practitioners, direct alpha-C-H bond functionalization of unprotected alicyclic amines is rare. A new method utilizing N-lithiated alicyclic amines has been developed, providing a convenient approach to achieve functionalization reactions under mild conditions. This method offers a new pathway for the synthesis of beta-amino ketones with regioselective alpha'-alkylation, and potential for one-pot synthesis of polycyclic dihydroquinolones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Zhengbo Zhu, Minami Odagi, Nantamon Supantanapong, Weici Xu, Jaan Saame, Helmi-Ulrika Kirm, Khalil A. Abboud, Ivo Leito, Daniel Seidel
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Organic
Jae Hyun Kim, Anirudra Paul, Ion Ghiviriga, Daniel Seidel
Summary: Enolizable cyclic imines obtained in situ from lithium amides by oxidation with simple ketone oxidants can be readily alkylated with a range of enolates to provide mono- and polycyclic beta-aminoketones in a single operation, including the natural product (+/-)-myrtine. Nitrile anions also serve as competent nucleophiles in these transformations promoted by BF3 etherate. Moreover, beta-aminoesters derived from ester enolates can be converted to the corresponding beta-lactams.
Article
Chemistry, Organic
Weijie Chen, Daniel Seidel
Summary: Polycyclic lactams are prepared in a single operation from otoluamides and cyclic amines, utilizing transient cyclic imines generated in situ from lithium amides and simple ketone oxidants. The annulation process involves imines like 1-pyrroline and 1-piperideine engaging lithiated o-toluamides, with undesired side reactions suppressed through careful selection of reaction conditions.
Article
Chemistry, Organic
Daniel A. Valles, Subhradeep Dutta, Anirudra Paul, Khalil A. Abboud, Ion Ghiviriga, Daniel Seidel
Summary: This one-pot procedure allows for the sequential, regioselective, and diastereoselective introduction of the same or two different substituents to the alpha- and alpha'-positions of unprotected azacycles using corresponding organolithium compounds. Various azacycles like pyrrolidines, piperidines, azepanes, and piperazines are included in the scope of this transformation.
Review
Chemistry, Organic
Weijie Chen, Daniel Seidel
Summary: This review provides a comprehensive overview of condensation-based methods for C-H bond functionalization of amines using azomethine ylides as key intermediates, which allow rapid transformation of simple starting materials into complex amines.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Organic
Subhradeep Dutta, Bowen Li, Dillon R. L. Rickertsen, Daniel A. Valles, Daniel Seidel
Summary: This review provides a concise overview of the methods that enable the functionalization of sp(3) C-H bonds in amines and their derivatives.
Article
Chemistry, Organic
Anirudra Paul, Camille Vasseur, Scott D. Daniel, Daniel Seidel
Summary: Relatively unstable cyclic imines, generated from alicyclic amines via oxidation of their lithium amides with simple ketone oxidants, react with aryllithium compounds containing a leaving group on an ortho-methylene functionality to form polycyclic isoindolines in a single step. The transformation can be applied to pyrrolidine, piperidine, azepane, azocane, and piperazine.
Article
Chemistry, Multidisciplinary
Alafate Adili, Angie B. Korpusik, Daniel Seidel, Brent S. Sumerlin
Summary: Visible light-mediated direct decarboxylation is a versatile technique for the synthesis of functional materials with tailored compositions and properties. This process allows for the generation of carbon-centered radicals in polymer chains without the need for preactivation of acid groups. It can be used to obtain challenging copolymers and trigger degradation of polymer backbones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Sharath Chandra Mallojjala, Victor O. Nyagilo, Stephanie A. Corio, Alafate Adili, Anuradha Dagar, Kimberly A. Loyer, Daniel Seidel, Jennifer S. Hirschi
Summary: The mechanistic study of three intermolecular anti-Markovnikov alkene hydrofunctionalization reactions has provided detailed insights into the reaction pathways and rate-limiting steps. These findings can guide the development of asymmetric versions of these reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Fuchao Yu, Daniel A. Valles, Weijie Chen, Scott D. Daniel, Ion Ghiviriga, Daniel Seidel
Summary: Secondary alicyclic amines are converted to alpha-aminonitriles by adding TMSCN to their corresponding imines, which are generated in situ via the oxidation of amine-derived lithium amides with simple ketone oxidants. Amines with an existing a-substituent undergo regioselective alpha'-cyanation, even if the C-H bonds at that site are less activated. Amine alpha-arylation can be combined with alpha'-cyanation to produce difunctionalized products in a single step.
Article
Chemistry, Organic
Alafate Adili, Aniket V. V. Sole, Bishwaprava Das, Megan E. Matter, Daniel Seidel
Summary: In the presence of a thiourea-carboxylic acid catalyst, N-9-fluorenyltryptamines undergo highly enantioselective Pictet-Spengler reactions with a range of aldehydes. The reaction exhibits good compatibility with aromatic aldehydes, accepting diverse substituents at various positions on the ring. Electron-deficient tryptamines can also be used as substrates. Furthermore, the fluorenyl protecting group can be easily removed without affecting the enantioselectivity of the product.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Alafate Adili, John-Paul Webster, Chenfei Zhao, Sharath Chandra Mallojjala, Moises A. Romero-Reyes, Ion Ghiviriga, Khalil A. Abboud, Mathew J. Vetticatt, Daniel Seidel
Summary: The enantioselective oxa-Pictet-Spengler reactions of tryptophol with aldehydes were successfully conducted under weakly acidic conditions using a combination of indoline HCl salt and bisthiourea compound as catalysts. Mechanistic investigations determined the roles of both catalysts and confirmed the involvement of oxocarbenium ion intermediates, ruling out alternative scenarios. A stereochemical model derived from density functional theory calculations provided the basis for the development of a highly enantioselective stereodivergent variant with racemic tryptophol derivatives.
Article
Chemistry, Organic
Dillon R. L. Rickertsen, Longle Ma, Anirudra Paul, Khalil A. Abboud, Daniel Seidel
