Article
Chemistry, Organic
Ajmir Khan, Luiz F. Silva, Muhammad Rabnawaz
Summary: This study presents a metal-free approach for the synthesis of seven-membered heterocycles (chromane, thiochromane) or rings fused with heterocycles (furan, indole, pyrrole, and thiophene) through the ring expansion of methylenic heterocycles mediated by the iodine(III) reagent HTIB in aqueous acetonitrile.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Physical
Riccardo Giovanelli, Giulio Bertuzzi, Marco Bandini
Summary: The utilization of CO2 as an efficient and environmentally friendly chemical analogue of CO is becoming a solid reality in the chemical scenario. CO2-based carbonylations have started paralleling the more consolidated carboxylation procedures, opening new horizons and perspectives in the utilization of carbon dioxide as an organic C1-containing building block. The advent of efficient and site-selective metal-catalyzed protocols for the fixation of CO2 into organic scaffolds, under controlled reductive conditions, contributed substantially to the development of robust, efficient, and convenient protocols. In the present Review article, a collection of the most recent examples of metal-catalyzed CO2-based carbonylations is documented with a particular emphasis on mechanistic aspects.
Review
Chemistry, Multidisciplinary
Paolo Destito, Cristian Vidal, Fernando Lopez, Jose L. Mascarenas
Summary: Developing non-natural biocompatible transformations in biologically relevant media has attracted significant interest in the past decade, with the use of transition metal complexes offering unique possibilities. This translation of metal catalyst potential to biological environments poses challenges, but describing the most relevant advances and key challenges helps identify issues from an organometallic perspective.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Nhan N. H. Ton, Binh Khanh Mai, Thanh Vinh Nguyen
Summary: Hydroboration reaction of alkynes is an efficient tool for accessing organoboron compounds, and a novel method using tropylium salts as catalysts has been reported for metal-free hydroboration. This method allows easy access to a wide range of vinylboranes. Experimental studies and DFT calculations revealed an uncommon mechanistic pathway triggered by the hydride abstraction of pinacolborane with tropylium ion.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Michael Schaefer, Timo Stuenkel, Constantin G. Daniliuc, Ryan Gilmour
Summary: The regio- and enantioselective intermolecular vicinal fluoroamination of alpha-trifluoromethyl styrenes has been achieved through enantioselective I-I/I-III catalysis, providing facile access to tertiary benzylic stereocenters bearing both CF3 and F groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Tsugio Kitamura, Daichi Kitamura, Juzo Oyamada, Masahiro Higashi, Yosuke Kishikawa
Summary: A new N-F reagent, N,N'-difluoro-2,2';-bipyridinium bis(tetrafluoroborate), for iodoarene-catalyzed fluorination reactions as a terminal oxidant is reported. This reaction is effective for the fluorination of simple alkenes, aromatic alkenes and 1,3-dicarbonyl compounds, giving 1,2-difluorinated alkanes, geminal difluorinated compounds, 2-fluorinated-1,3-dicarbonyl compounds in good to high yields, respectively. The present N-F reagent can be recovered as 2,2'-bipyridine.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Man Xu, Yuanzhi Xia
Summary: Density functional theory (DFT) calculations revealed the mechanism of Rh(III)-catalyzed C-H activation/annulation reactions of N-phenoxyacetamides with methyleneoxetanones. Direct O-N bond cleavage to form a Rh(V)-nitrenoid species was energetically unfavorable, while sequential beta-H elimination/reductive elimination was more facile. The experimental outcomes were explained by the catalytic cycle of Rh(III)/Rh(I)/Rh(III) suggested by DFT.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Zhihao Qi, Jinwei Zhuang, Wantong Yang, Yonggang Yang, Ling Wang, Chenyang Cai, Zhilin Zhang, Yutao Hua, Dilnur Abdirazik, Longhua Li, Weidong Shi, Jinhui Hao
Summary: In this study, a symmetrical waveform alternating current strategy is introduced for obtaining gradient oxygen vacancies (V-O) in situ. The unique gradient V-O offers multiple steps to reduce reaction kinetics, resulting in a significant increase of up to 84.7% in current density.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Rok Narobe, Kathiravan Murugesan, Simon Schmid, Burkhard Koenig
Summary: This study presents a metal-free system based on iodine (I/III) catalytic manifold that can generate carbenium ion intermediates at electronically disfavored positions. The system exhibits unusually high reactivity due to the complexation of iodine (III) intermediates with BF3. Detailed mechanistic investigations suggest two possible pathways for the decarboxylative Ritter-type amination protocol.
Article
Chemistry, Applied
Yuki Umakoshi, Yusuke Takemoto, Akira Tsubouchi, Viktor V. Zhdankin, Akira Yoshimura, Akio Saito
Summary: A transition metal iodine catalyst is used to synthesize oxazoles through C-C bond formation between unfunctionalized alkynes and arenes, resulting in the introduction of aryl groups into the side chain of the compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
You-Jie Yu, Joel Haefliger, Zi-Xuan Wang, Constantin G. Daniliuc, Ryan Gilmour
Summary: A main-group catalysis-based strategy for accessing 8-membered carbocycles via direct carbofunctionalization of 2-phenethyl-substituted 1,3-dienes is presented. By utilizing an I(I)/I(III) catalysis cycle, densely functionalized, fluorinated benzocyclooctenes can be synthesized in a straightforward manner. The process, which involves modulation of the oxidation/activation regime and the external nucleophile, has been extended to enable the cyclization with allylic C-O, C-N, and C-C bond formation (>30 examples).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Nagarajan Ramkumar, Larisa Baumane, Dzintars Zacs, Janis Veliks
Summary: A simple process for the oxy-monofluoromethylation of alkenes is presented. The use of visible-light copper(I) photoredox catalysis, in combination with an easily accessible iodine(III) reagent containing monofluoroacetoxy ligands, enables the synthesis of gamma-fluoro-acetates from various olefinic substrates under mild conditions. The study also demonstrates its applications in late-stage diversification of complex molecules, amino acids, and the synthesis of fluoromethylated heterocycles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tyler W. Reidl, Jeffrey S. Bandar
Summary: The Lewis basic salts facilitate the coupling of benzyltrimethylsilane with (hetero)aryl nitriles, sulfones, and chlorides, providing a new route to 1,1-diarylalkanes with high selectivity. This method shows great potential in the synthesis of pharmaceutical analogues and multicomponent reactions, offering a complementary scope to existing methods.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Harshita Shet, Krishna Chaitanya Gunturu, Santosh J. Gharpure, Saidurga Prasad Kommyreddy, Krishna S. Gupta, Smruti Rekha Rout, Rambabu Dandela, Anant R. Kapdi
Summary: In this study, the highly regioselective nucleophilic aromatic substitution (SNAr) of polychlorinated pyrimidines promoted by Cu(II)/PTABS is reported, aided by DFT predictions of bond dissociation energies. The unique reactivity of Cu(II)-PTABS is attributed to its coordination/activation mechanism, with further insights into the catalytic species provided.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Wu Fufang, Li Xuejian, Jia Hao, Han Xuanzhen, Shen Xiaobao
Summary: The synthesis of oxygen-substituted N-hydroxy phthalimide derivatives through dehydrogenation of olefins, a-oxidation of carbonyl compounds, oxidation of aldehydes, and oxidative esterification of primary alcohols using iodobenzene diacetate and N-hydroxy phthalimide as precursors, provides a mild metal-free reaction conditions with good compatibility and wide substrate scope.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Raghavan B. Sunoj
Summary: Computational chemistry has evolved into a highly interdisciplinary domain, shaping our molecular view of the world. This essay covers the historic, personal, and most modern manifestations of computational chemistry.
ISRAEL JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Manajit Das, Achyut Ranjan Gogoi, Raghavan B. Sunoj
Summary: In this paper, the molecular understanding of the role of protic solvents in organic transformations is explored using density functional and ab initio computational studies. The inclusion of explicit solvent molecules in crucial transition states has been found to improve the energetic estimates of organocatalytic and transition-metal-catalyzed reactions. An overview of the importance of an explicit-implicit solvation model is provided with the help of interesting examples.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Supratim Ghosh, Shilpa Shilpa, C. Athira, Raghavan B. Sunoj
Summary: This review highlights the importance of additives in transition metal catalyzed reactions and the establishment of molecular understanding of their role using modern computational chemistry tools. Explicit consideration of additives is crucial in identifying a more reasonable reaction mechanism of catalytic reactions.
TOPICS IN CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Soumi Tribedi, Raghavan B. Sunoj
Summary: The article discusses a novel method of chiral induction, utilizing DAPCy as a chiral catalyst to form chiral pyrrolidine derivatives through intramolecular nucleophilic addition, achieving a quantum conversion with 95% ee.
Article
Chemistry, Multidisciplinary
Md Emdadul Hoque, Ranjana Bisht, Anju Unnikrishnan, Sayan Dey, Mirja Md Mahamudul Hassan, Saikat Guria, Rama Nand Rai, Raghavan B. Sunoj, Buddhadeb Chattopadhyay
Summary: A method of para-selective borylation of aromatic amides is described using a newly designed ligand framework (defa), which shows excellent selectivity and reactivity for the para position. This method can contribute to the development of new catalytic systems and the synthesis of para-functionalized compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Manajit Das, Pooja Sharma, Raghavan B. Sunoj
Summary: The integration of machine learning into chemical catalysis has become a new paradigm for reaction development. In this study, a ML workflow was developed to predict the enantioselectivity of a class of catalytic asymmetric transformation, namely the relay Heck reaction. The ML model, built using quantum chemically derived descriptors, showed a remarkable prediction accuracy and assisted in exploring unexplored reactions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Organic
Mirja Md Mahamudul Hassan, Biplab Mondal, Sukriti Singh, Chabush Haldar, Jagriti Chaturvedi, Ranjana Bisht, Raghavan B. Sunoj, Buddhadeb Chattopadhyay
Summary: An efficient method for ligand-free Ir-catalyzed ortho borylation of arenes has been developed, which can be applied to various important compounds and pharmaceuticals. The mechanistic pathway of the reaction has been revealed through detailed investigations. The method displays a broad substrate scope and functional group tolerance, and has achieved successful borylation of various important molecules and drugs.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Sukriti Singh, Raghavan B. Sunoj
Summary: Sustainable practices in chemical sciences can be better achieved by adopting interdisciplinary approaches that combine the advantages of machine learning in reaction discovery with small initial data. The use of a recurrent neural network-based deep generative model allows for effective learning and exploration of the chemical space, generating high-quality novel alcohol molecules.
Review
Chemistry, Multidisciplinary
Sukriti Singh, Raghavan B. Sunoj
Summary: In reaction development, higher efficiencies are desired and machine learning models can predict reaction outcomes for new choices of substrates/catalysts. However, applying machine learning to reaction discovery is challenging due to difficulties in molecular featurization, availability of quality data, and the choice of suitable models and their deployment. Feature engineering and feature learning methods can be effective in predicting reaction outcomes.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Supratim Ghosh, Avtar Changotra, David A. Petrone, Mayuko Isomura, Erick M. Carreira, Raghavan B. Sunoj
Summary: In this study, the mechanism of a chiral Ir-phosphoramidite-catalyzed asymmetric reductive deoxygenation reaction was investigated using density functional theory. It was found that Bi(OTf)3 promotes ionic and noncovalent interactions, which play a crucial role in nucleophile selectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
C. Athira, A. Sreenithya, Christopher M. Hadad, Raghavan B. Sunoj
Summary: The increasing number of examples on cooperative dual catalysis involving organocatalysts and transition metal catalysts indicate their wider acceptance and utility in synthetic applications. In this study, computational investigation using density functional theory reveals the molecular mechanism and energetic features responsible for the high enantio-/diastereoselectivities and cooperativity in dual catalytic reactions.
Review
Chemistry, Physical
Shilpa Shilpa, Gargee Kashyap, Raghavan B. Sunoj
Summary: The burgeoning developments in machine learning have found notable applications in chemistry, particularly in the prediction of molecular properties and chemical reactions. This review highlights the recent advancements in ML implementations, ranging from ensemble-based models to graph neural networks. Accurate predictions in molecular property prediction, using methods such as D-MPNN, MolCLR, SMILES-BERT, and MolBERT, offer promising prospects in molecular design and drug discovery. Challenges in dealing with reaction data sets are discussed, alongside an optimistic outlook on the benefits of ML-driven workflows for various chemistry tasks.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Sandip Kumar Das, Subrata Das, Supratim Ghosh, Satyajit Roy, Monika Pareek, Brindaban Roy, Raghavan B. Sunoj, Buddhadeb Chattopadhyay
Summary: A new iron-porphyrin based catalytic system has been developed for intramolecular C-H amination of substituted tetrazolopyridines. This method exhibits high regioselectivity and excellent functional group tolerance, enabling the synthesis of three different classes of high-value N-heterocyclic scaffolds. The study also reveals the metalloradical activation mechanism of this catalytic system.
Article
Chemistry, Physical
Soumi Tribedi, Kazuo Kitaura, Takahito Nakajima, Raghavan B. Sunoj
Summary: The study delves into the origin of selectivity in asymmetric catalysis, revealing that weak noncovalent interactions can sometimes outweigh steric effects in enantiocontrolling transition states. By using the fragment molecular orbital method, the relative contributions of various attractive and repulsive interactions in the total interaction energy in enantiocontrolling transition states can be determined. This quantitative insight on intramolecular interactions may aid in the rational design of asymmetric catalysis.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Review
Chemistry, Multidisciplinary
Monika Pareek, Yernaidu Reddi, Raghavan B. Sunoj
Summary: N-Heterocyclic carbenes (NHCs) are popular organocatalysts known for their umpolung reactivity on aldehydes and ketones. Recent research has focused on gaining insights into the formation and characterization of Breslow intermediates, which play a central role in organocatalytic reactions.
