Article
Chemistry, Multidisciplinary
Shuailong Li, Dequan Zhang, Runtong Zhang, Shao-Tao Bai, Xumu Zhang
Summary: This article reports a novel rhodium catalyst that enables highly efficient and selective hydroformylation of cyclopropyl-functionalized trisubstituted alkenes, resulting in valuable chiral cyclopropyl entities. The modified ligand used in this study exhibits superior performance compared to traditional diphosphine ligands in asymmetric catalysis. Gram-scale reactions and subsequent transformations of the products were also demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Chaoyan Ma, Can Li, Jiahui Bai, Junzhe Xiao, Yizhan Zhai, Yinlong Guo, Shengming Ma
Summary: In this study, a rhodium-catalyzed C-H functionalization-based intermolecular allylation of indoles with trisubstituted allenes has been developed. The synthetic process demonstrates excellent regioselectivity, Z-selectivity, high efficiency of chirality transfer, and a wide tolerance of reactive functional groups under mild conditions. Late-stage modification on complex bioactive or drug molecules has been achieved, along with various synthetic transformations. A reaction mechanism has been proposed based on mechanistic experiments and SAESI-MS studies.
Article
Chemistry, Organic
Ke-Qin Wu, Hui Li, Ao Zhou, Wei-Ran Yang, Qin Yin
Summary: A Pd-catalyzed regioselective C-H bond allylic alkylation of phenols with 1,3-dienes is reported, which selectively functionalizes the ortho C-H bond of 2-naphthols, 1-naphthols, and electron-rich phenols to synthesize phenol derivatives with diverse structures. The reaction is accelerated by a diphosphine ligand, does not require any other additive, and exhibits broad substrate scope and good chemo- and regioselectivity. Additionally, an asymmetric variant is investigated, achieving product with up to 55% enantiomeric excess.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zhili Liu, Lianfen Chen, Dong Zhu, Shifa Zhu
Summary: A highly efficient formal allylation of dihydronaphthotriazoles with alkenes under rhodium(II) catalysis is reported. Various allyl dihydronaphthalene derivatives were obtained with moderate to good yields and excellent chemoselectivity through rhodium(II) azavinyl carbenes. Notably, the allylic C(sp(2))-H activation occurs instead of the traditional C(sp(3))-H activation in the formal allylation process, and good to excellent enantioselectivities are achieved when monosubstituted alkenes are used.
Article
Chemistry, Organic
Qiongya Li, Tian Chen, Jiangtao Sun
Summary: A phosphoric acid-catalyzed regio- and enantioselective N-2-propargylation of pyridazinones has produced chiral N-2-alkylated pyridazinones with moderate to good yields (up to 93%) and good enantioselectivities (up to 96% ee). Furthermore, by slightly modifying the reaction conditions, the chemo- and enantioselective N-alkylation of 2-pyridones has also been achieved (up to 88% yield, 96% ee).
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Weilin Wang, Youliang Wang
Summary: In this study, a novel reaction method using diaryliodonium salts to promote multicomponent trifunctionalization of alkynes was reported. The reaction showed high selectivity in functionalizing alkynes and generated a diverse range of complex structures.
Article
Multidisciplinary Sciences
Lei Wang, Chuiyi Lin, Qinglei Chong, Zhihan Zhang, Fanke Meng
Summary: Catalytic enantioselective introduction of a propargyl group is an important carbon-carbon forming reaction, but only a few Cu- or Ni-catalyzed protocols with limited reaction modes are known. Here, the authors describe a photoredox/cobalt-catalyzed propargyl addition to aldehydes via propargyl radicals which enables the construction of a broad scope of homopropargyl alcohols that are otherwise difficult to access. Mechanistic studies and DFT calculations provide evidence for the involvement of propargyl radicals, the origin of the stereoconvergent process, and the stereochemical models.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ryota Shimotsukue, Kohei Fujii, Yu Sato, Yuki Nagashima, Ken Tanaka
Summary: We have developed a rhodium-catalyzed intermolecular [2+2+2] cycloaddition reaction with excellent selectivity, producing chiral cyclohexadienylamines. The reaction involves the reaction of two arylacetylenes with a cis-enamide or a silylacetylene to yield the desired products with complete regio- and diastereoselectivity and high yields and enantioselectivity. Mechanistic studies suggest the formation of a rhodacyclopentadiene intermediate from the terminal alkynes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Liang-Feng Yang, Qiu-An Wang, Jin-Heng Li
Summary: This study presents a new method for the palladium-/copper-cocatalyzed three-component trans-allenylsilylation of terminal alkynes with propargyl acetates and PhMe(2)SiBpin, providing a highly chemoselective, regioselective, and stereoselective alkyne difunctionalization route to the synthesis of valuable (E)-silyl enallenes. The utility of this method is demonstrated through late-stage derivatization of bioactive compounds.
Article
Chemistry, Multidisciplinary
Sheng Feng, Stephen L. Buchwald
Summary: A method for preparing alpha-chiral carboxylic acid derivatives, including those with all-carbon quaternary centers, was reported through an enantioselective CuH-catalyzed hydrocarboxylation of allenes with a commercially available fluoroformate. Various heterocycles and functional groups on the allenes were tolerated, resulting in enantioenriched alpha-quaternary and tertiary carboxylic acid derivatives with good yields and exclusive branched regioselectivity. The synthetic utility of this approach was further demonstrated by derivatization of the products to obtain biologically important compounds, such as the antiplatelet drug indobufen.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Sajid Ur Rehman, Changkun Li
Summary: A highly regio- and enantioselective allylic sulfonation was achieved by using rhodium and bisoxazolinephosphine (NPN*) ligands, starting from racemic branched allylic carbonates and readily available sulfonylhydrazides under neutral conditions. The reaction produced branch-selective allylic sulfones with a >20:1 branch:linear ratio and >99% enantiomeric excess (ee) in <= 96% yield. Both Z and E linear allylic carbonates could also be transformed into the same chiral branched allylic sulfones with high regio- and enantioselectivities.
Article
Chemistry, Multidisciplinary
Li-Xia Liu, Yu-Qing Bai, Xiang Li, Chang-Bin Yu, Yong-Gui Zhou
Summary: Combining base-promoted retro-sulfa-Michael addition with palladium-catalyzed asymmetric allenylic alkylation, a streamlined synthesis of chiral thiochromanones containing two central chiralities (including a quaternary stereogenic center) and an axial chirality (allene unit) was successfully achieved, with yields up to 98%, dr of 49.0:1, and >99% ee.
Article
Chemistry, Organic
Renren Li, Haocheng Zhang, Bangkui Yu, Hanmin Huang
Summary: A novel palladium-catalyzed cascade annulative aminomethylamination of diene-tethered enynes with aminals is reported. This method allows for the efficient synthesis of functionalized benzofulvenes with excellent chemo- and regioselectivities, as well as high atom economy. Mechanistic studies reveal the preferential reaction of alkylpalladium species with 1,3-enyne over 1,3-diene in initiating the cyclizative aminomethylamination.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Timm Bury, Sven Kullmann, Bernhard Breit
Summary: Here, a highly branched regioselective nickel(0)-catalyzed hydrocyanation of mono- and 1,1-disubstituted allenes as well as an asymmetric hydrocyanation of 1,1-disubstituted allenes is reported, providing access to branched tertiary and quaternary beta,gamma-allylic nitriles. The regioselective hydrocyanation of terminal allenes using a nickel(0)/Biphephos catalytic system offers yields up to 96% and is applicable to a substrate scope containing various functional groups. The catalytic system of Ni(0)/TADDOL-based bisphosphite catalyst enables the synthesis of branched quaternary allylic nitriles with yields up to 99% and enantioselectivities up to 86%.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Inorganic & Nuclear
Rifhat Bibi, Amna Murtaza, Khalid Mohammed Khan, Zia Ur Rehman, Aamer Saeed, Muhammad Nawaz Tahir, Abbas Hassan
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
(2020)
Article
Biochemistry & Molecular Biology
Haseen Ahmad, Faisal Ahmad, Shaista Parveen, Sajjad Ahmad, Syed Sikander Azam, Abbas Hassan
BIOORGANIC CHEMISTRY
(2020)
Article
Chemistry, Medicinal
Haseen Ahmad, Saif Ullah, Fouzia Rahman, Aamer Saeed, Julie Pelletier, Jean Sevigny, Abbas Hassan, Jamshed Iqbal
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2020)
Article
Chemistry, Medicinal
Maria Bibi, Naveeda Akhter Qureshi, Abdul Sadiq, Umar Farooq, Abbas Hassan, Nargis Shaheen, Irfa Asghar, Duaa Umer, Azmat Ullah, Farhan A. Khan, Muhammad Salman, Ahtaram Bibi, Umer Rashid
Summary: Efforts to find efficient therapeutic drug targets for leishmaniasis have focused on DHFR. This study aimed to design and synthesize selective antifolates targeting L. major, with compound 59 showing potent inhibition of the parasite. Selectivity for LmDHFR over human DHFR was demonstrated, with compounds 56 and 58 showing the highest selectivity.
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Aamer Saeed, Atteeque Ahmed, Pervaiz Ali Channar, Ghulam Shabir, Abbas Hassan, Zia-ur-Rehman, Qamar Abbas, Mubashir Hassan, Hussain Raza, Sung-Yum Seo, Hesham R. El-Seedi
Summary: Tyrosinase is a multi-copper enzyme that plays a critical role in melanogenesis and browning process important to cosmetics and food industries. A series of symmetrical Bis-Azo-Azamethine hybrids were synthesized and compound 5i was found to be the most potent inhibitor with strong free radical scavenging activity, suggesting its potential applications in inhibiting melanogenesis and oxidative stress.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2022)
Article
Chemistry, Organic
Rabail Ujan, Pervaiz Ali Channar, Aamer Saeed, Qamar Abbas, Hummera Rafique, Saba Ashraf, Mahboob Ali Rind, Abbas Hassan, Anwar Ul-Hamid, Mubashar Hassan, Hussain Raza, Sung-Yum Seo
Summary: The study identified compound 4f as the most significant elastase inhibitor, with compounds 4e and 4i showing remarkable free-radical scavenging activity. Compound 4f had a binding energy of 7.2 kcal/mol and showed competitive inhibition of pancreatic elastase in kinetics studies.
JOURNAL OF HETEROCYCLIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Amna Murtaza, Saira Afzal, Gohar Zaman, Aamer Saeed, Julie Pelletier, Jean Sevigny, Jamshed Iqbal, Abbas Hassan
Summary: A series of substituted quinoline derivatives were synthesized and evaluated for their inhibitory activities against human nucleoside triphosphate diphosphohydrolases (h-NTPDases), showing some compounds with significant activity and selectivity towards specific isoenzymes. Molecular docking studies further confirmed the potential of quinoline scaffold as potent and selective NTPDase inhibitors.
BIOORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Pervaiz Ali Channar, Mubashir Aziz, Syeda Abida Ejaz, Gul-e-Saba Chaudhry, Amna Saeed, Rabail Ujan, Abbas Hasan, Syeda Rabia Ejaz, Aamer Saeed
Summary: The synthesis of compounds with a thiazolidinone pharmacophore was achieved, and their anticancer activities were evaluated. Compounds 2c and 2d exhibited significant cytotoxicity against MCF-7 and HeLa cell lines by inducing apoptosis. Molecular docking and dynamic simulations provided further support to these findings, and computational studies suggested the potential of these compounds as lead molecules for the development of novel drug candidates for specific cancers.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2023)
Review
Chemistry, Organic
Ahsanullah, Abbas Hassan, Farzana L. Ansari, Joerg Rademann
Summary: The modification of native peptides to peptidomimetics is an important goal in medicinal chemistry, and using Meldrum's acid and phosphorus and sulfur ylides for peptide-compatible C-acylation is an effective method to achieve this goal.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Haseen Ahmad, Waqar Ahmed, Abbas Hassan
Summary: Copper-mediated transformation enables the successful C-N coupling of thiazole appendant aryl halides with various amides, leading to the formation of amide products with high yields.
Review
Chemistry, Medicinal
Abbas Hassan, Abid Hussain Khan, Faiza Saleem, Haseen Ahmad, Khalid Mohammed Khan
Summary: This review provides a comprehensive overview of the biological applications of oxadiazole-containing drugs from 2013 to 2021. Oxadiazoles have shown wide range of medicinal properties and have been widely used in medicinal chemistry, agriculture, and neuroprotection. The unique features of the oxadiazole scaffold make it a significant pharmacophore.
EXPERT OPINION ON THERAPEUTIC PATENTS
(2022)
Article
Chemistry, Organic
Rifhat Bibi, Ismat Ullah Khan, Abbas Hassan
Summary: A structure selectivity relationship was established by modifying the ligand structure, which greatly influenced the catalytic activity and selectivity of the catalyst for non-activated substrates in the Heck-Matsuda reaction. The ligand 6MesPyoxsBu showed optimal catalytic activity and selectivity.
TETRAHEDRON LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Zahra Begum, Saif Ullah, Muhammad Akram, Muhammad Uzair, Farman Ullah, Ahsanullah, Julie Pelletier, Jean Sevigny, Jamshed Iqbal, Abbas Hassan
Summary: A series of thienopyrimidines were synthesized and screened for their inhibitory activity against h-NTPDases. Molecular docking study revealed the interactions between these compounds and important amino acid residues of the respective h-NTPDase isozymes.
BIOORGANIC CHEMISTRY
(2022)
Article
Chemistry, Medicinal
Gohar Zaman, Saif Ullah, Muhammad Uzair, Sania Batool, Haseen Ahmad, Farman Ullah, Julia Pelletier, Jean Sevigny, Jamshed Iqbal, Abbas Hassan
Summary: In this study, various thieno[3,2-d]pyrimidine derivatives were synthesized by treating different secondary amines through aromatic nucleophilic substitution reaction (SNAr) followed by Suzuki reaction. The synthesized compounds were screened for their hydrolytic activity inhibition against h-NTPdase1, h-NTPdase2, h-NTPdase3, and h-NTPdase8. Compound N-benzyl-N-methyl-7-phenylthieno[3,2-d]pyrimidin-4-amine 3j selectively inhibited h-NTPdase1 activity with an IC50 value of 0.62 +/- 0.02 µM, while compound 4d was the most potent inhibitor of h-NTPdase2 with a sub-micromolar IC50 value of 0.33 +/- 0.09 µM. Similarly, compounds 4c and 3b were found to be selective inhibitors for isozymes h-NTPdase3 (IC50=0.13 +/- 0.06 µM) and h-NTPdase8 (IC50=0.32 +/- 0.10 µM), respectively. Molecular docking study revealed the interactions with important amino acid residues.
Article
Polymer Science
Asad Ullah, Syed M. Shah, Abbas Hassan, Milan Maric, Hazrat Hussain
JOURNAL OF POLYMER SCIENCE
(2020)
