Article
Chemistry, Organic
Peter Langer
Summary: This article presents a personalized account of 1,1-dia-cyclopropanes as synthetic building blocks or target molecules. The chemistry discussed includes cyclization reactions of 1,1-diacylcyclopropanes with free and masked dianions, resulting in spirocyclopropanes as products or reactive intermediates. Additionally, the synthesis of cyclopropylated 1,3,5-tricarbon-yl compounds, containing two 1,1-diacylcyclopropane moieties, is also discussed. Based on this work, other syntheses of cyclopropanes were developed.
Article
Chemistry, Organic
Peter Langer
Summary: This article focuses on the reactions of epichlorohydrin and epibromohydrin with free and masked dianions. These reactions offer convenient syntheses of various products, such as 2-(alkylidene)tetrahydrofurans (which can be further functionalized), cyclopropanes, ?-butyrolactams, oxazines, oxazolo[3,4-b]pyridazin-7-ones, or 2-(alkylidene)thiazolidines. Overall, the reactions exhibit excellent regioselectivity.
Article
Chemistry, Multidisciplinary
Wenke Dong, Zhiyang Ye, Wanxiang Zhao
Summary: Catalytic asymmetric hydroboration of ketone-derived silyl enol ethers using cobalt catalyst has been reported, providing a convenient approach to access valuable enantiopure beta-hydroxy boronic esters. This method features mild reaction conditions, a broad substrate scope, and excellent enantioselectivities, making it potential to streamline the synthesis of complex molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Peter Langer
Summary: This article discusses the reactions and applications of the dianion of 1,1-diphenylacetone. A new allene synthesis was serendipitously discovered through the study of the regioselectivity of these reactions. Additionally, the reactions of allene dianions with various electrophiles have been investigated.
Article
Chemistry, Inorganic & Nuclear
Joerg-Peter Guetlein, Mathias Lubbe, Holger Feist, Alexander Villinger, Peter Langer
Summary: The research successfully achieved the regioselective preparation of 4-methoxysalicylates and related polyketide-type phenols, and for the first time, cycloalkyl-substituted salicylates were synthesized.
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Kun Liu, Armido Studer
Summary: This study presents a method for the formal beta-C-H arylation of aldehydes and ketones using cooperative nickel and photoredox catalysis, which exhibits wide scope and tolerance towards functional groups. Additionally, it enables beta-alkenylation, beta-alkynylation, and beta-acylation of aldehydes under similar conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Suresh Kumar, Markus Lange, You Zi, Helmar Goerls, Ivan Vilotijevic
Summary: Using silylated compounds as latent pronucleophiles allows for the enantioselective allylation of common stabilized C-nucleophiles with allylic fluorides, overcoming the limitations of Lewis base catalyzed allylations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Ransong Ma, Zhoubin Deng, Ke-Hu Wang, Junjiao Wang, Danfeng Huang, Yingpeng Su, Yulai Hu, Xiaobo Lv
Summary: An efficient and novel photoinduced trifluoromethylation using CF3Br as a trifluoromethyl source is described. With commercially accessible fac-Ir(III)(ppy)3 as the catalyst, successful radical trifluoromethylation between O-silyl enol ether and CF3Br occurs. This method provides various alpha-CF3-substituted ketones with a broad substrate scope in good yields under mild reaction conditions.
Article
Chemistry, Organic
Natalie C. Dwulet, Vincenzo Ramella, Christopher D. Vanderwal
Summary: Soft enolization conditions are shown to be more efficient than hard enolization protocols in regioselectively forming enoxysilanes from unsymmetrical 3-substituted cycloalkanones. The regioselectivities achieved are complementary to those obtained from cycloalkenone conjugate addition/enolate silylation with high selectivity.
Article
Chemistry, Multidisciplinary
Tsubasa Nakashima, Haruka Fujimori, Kohsuke Ohmatsu, Takashi Ooi
Summary: Intermediary radical cations, generated through single-electron oxidation of enol silyl ethers by excited Ir-based photocatalysts, are exploited as Bronsted acids for activating heteroarylcyanides. This enables the direct allylic C-H heteroarylation of enol silyl ethers under visible-light irradiation.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Chenhao Zhang, Anthony Z. Gao, Xin Nie, Chen-Xi Ye, Sergei I. Ivlev, Shuming Chen, Eric Meggers
Summary: This study demonstrates the catalytic deracemization of ketones with alpha-stereocenters in a single reaction through photoredox deprotonation and enantioselective protonation. By utilizing a photoredox catalyst and a tertiary amine, nonracemic carbonyl compounds with up to 97% enantiomeric excess can be obtained. This light-driven strategy provides a blueprint for deracemizations of common carbonyl compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Xiaowu Fang, Songwei Wen, Peishen Jin, Wenjing Bao, Shanshan Liu, Hengjiang Cong, Xiao Shen
Summary: Fluorinated enol silanes are widely used in synthetic transformations, but previous methods only allowed for the synthesis of racemic products. In this study, an enantioselective reductive coupling reaction was developed to access enantioenriched fluorinated enol silanes. The practicality of this methodology was demonstrated through multistep-one-isolation processes, and the synthetic potential of enantioenriched fluorinated enol silanes in the synthesis of valuable chiral organofluorine compounds was also shown.
Article
Chemistry, Organic
Marina Briand, Linh D. Thai, Flavien Bourdreux, Nicolas Vanthuyne, Xavier Moreau, Emmanuel Magnier, Elsa Anselmi, Guillaume Dagousset
Summary: Site-selective trifluoromethylation of silyl dienol ethers derived from alpha,ss-unsaturated aldehydes, ketones, and amides was achieved for the first time in the remote gamma position. An unprecedented enantioselective C(sp(3))-H perfluoroalkylation process is disclosed.
Article
Chemistry, Multidisciplinary
Dongxin Zhang, Lvjia Chen, Huiqing Deng, Ying Zhang, Qihang Cheng, Qian-Feng Zhang
Summary: Asymmetric ring-opening reactions of donor-acceptor cyclopropanes with 1,3-cyclodiones have been achieved for the synthesis of enantioenriched gamma-hydroxybutyric acid derivatives in the presence of Cu(ii)/trisoxazoline catalyst. These reactions provided the desired products in yields of 70% to 93% with enantiomeric excesses of 79% to 99%.
Review
Chemistry, Multidisciplinary
Vitalij V. Levin, Alexander D. Dilman
Summary: Interaction of enol ethers, enol acetates, enamides, and enamines with fluorinated reagents is a reliable method for synthesizing organofluorine compounds. Photoredox catalysis reveals the intrinsic reactivities of these components, which can proceed without a photocatalyst in some cases. The combination of electron donating and accepting components enables the necessary balance for individual redox steps and supports the key C,C-bond forming event.
Review
Chemistry, Multidisciplinary
Muhammad Ali A. Shah, Zeeshan Ali, Rasheed Ahmad, Ishtiaq Qadri, Kaneez Fatima, Nongyue He
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2015)
Review
Chemistry, Multidisciplinary
Rasheed Ahmad, Zeeshan Ali, Xianbo Mou, Jiuhai Wang, Huan Yi, Nongyue He
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2016)
Review
Chemistry, Multidisciplinary
Rasheed Ahmad, Juan Fu, Nongyue He, Song Li
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2016)
Article
Chemistry, Multidisciplinary
Zeeshan Ali, Jiuhai Wang, Xianbo Mou, Yongjun Tang, Taotao Li, Wenbiao Liang, Muhammad Ali A. Shah, Rasheed Ahmad, Zhiyang Li, Nongyue He
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2017)
Review
Chemistry, Multidisciplinary
Mubashir Hussain, Rasheed Ahmad, Yuan Liu, Bin Liu, Mu He, Nongyue He
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
(2017)
Review
Nanoscience & Nanotechnology
Rasheed Ahmad, Yan Deng, Ravina Singh, Mubashir Hussain, Muhammad Ali Abdullah Shah, Sauli Elingarami, Nongyue He, Yueming Sun
JOURNAL OF BIOMEDICAL NANOTECHNOLOGY
(2018)
Article
Chemistry, Inorganic & Nuclear
Rasheed Ahmad Khera, Munawar Hussain, Rasheed Ahmad, Aamer Saeed, Alexander Villinger, Christine Fischer, Peter Langer
JOURNAL OF FLUORINE CHEMISTRY
(2010)
Article
Chemistry, Organic
Muhammad Adeel, Muhammad A. Rashid, Nasir Rasool, Rasheed Ahmad, Alexander Villinger, Helmut Reinke, Christine Fischer, Peter Langer
SYNTHESIS-STUTTGART
(2009)
Article
Chemistry, Organic
Rasheed Ahmad Khera, Ihsan Ullah, Rasheed Ahmad, Abdolmajid Riahi, Nguyen Thai Hung, Muhammad Sher, Alexander Villinger, Christine Fischer, Peter Langer
Article
Chemistry, Organic
Munawar Hussain, Serge-Mitherand Tengho Toguem, Rasheed Ahmad, Dang Thanh Tung, Ingo Knepper, Alexander Villinger, Peter Langer
Article
Chemistry, Organic
Tung T. Dang, Rasheed Ahmad, Tuan T. Dang, Helmut Reinke, Peter Langer
TETRAHEDRON LETTERS
(2008)
Article
Chemistry, Organic
Rasheed Ahmad, Rasheed Ahmad Khera, Alexander Villinger, Peter Langer
TETRAHEDRON LETTERS
(2009)
Article
Chemistry, Multidisciplinary
Rasheed Ahmad Khera, Rasheed Ahmad, Ihsan Ullah, Obaid-Ur-Rahman Abid, Olumide Fatunsin, Muhammad Sher, Alexander Villinger, Peter Langer
HELVETICA CHIMICA ACTA
(2010)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
