Article
Chemistry, Medicinal
Gabriela Huelgas, Ratnasamy Somanathan, Julio M. Hernandez Perez, Haydee Rojas Cabrera, Maximiliano de la Higuera Macias, Alejandra Dominguez-Huerta, Rocio Sabala, Cecilia Anaya de Parrodi
Summary: This study synthesized novel organic compounds, and successfully carried out highly enantioselective and diastereoselective reactions using organocatalysts under solvent-free conditions in the presence of water, achieving effective stereoselective induction.
Article
Chemistry, Multidisciplinary
Caizhen Yue, Yasuhiro Yamashita, Shu Kobayashi
Summary: For the first time, catalytic enantioselective aldol reactions of trifluoroacetophenones with ketones were successfully developed under continuous-flow conditions using polystyrene-supported prolinamides. The robustness of the flow system was demonstrated by the continuous synthesis of various trifluoromethyl carbinols with high yields and enantioselectivities. Through mechanistic studies, it was revealed that the racemization phenomenon and reversible property of the aldol reactions in a conventional batch system could be suppressed under continuous-flow conditions.
Article
Chemistry, Multidisciplinary
Surendra Deepa, Surendra Singh
Summary: Imidazolium-based chiral ionic liquids containing prolinamide and prolinamide intercalated in bentonite clay were used for asymmetric aldol reactions. The chiral ionic liquid with S-phenylethylamine moiety catalyzed the enantioselective reaction of isatins and acetone, yielding 3-alkyl-3-hydroxy indolin-2-ones in good yields and enantioselectivities. Prolinamide intercalated in bentonite clay showed lower activity compared to the chiral ionic liquids. The prolinamide intercalated clay was recyclable for four cycles with a slight loss of activity and selectivity after the third cycle.
Article
Chemistry, Organic
Yiran Mo, Xuehuan Zhang, Yongqi Yao, Cong Duan, Ling Ye, Zhichuan Shi, Zhigang Zhao, Xuefeng Li
Summary: A sulfa-Michael/aldol/lactonization cascade reaction has been established to construct isotetronic acid-fused thiochromanes in a highly stereoselective fashion (>= 11:1 dr, 35-98% ee). The tricyclic products were obtained in 35-99% isolated yields in the presence of a bifunctional squaramide. Three reactive sites of beta,gamma-unsaturated alpha-ketoester, including the less-explored ester carbonyl group, were sequentially utilized to construct two fused heterocycles in a one-pot operation.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Azusa Kondoh, Masahiro Terada
Summary: In this review, the challenge of expanding the scope of pronucleophiles in the field of chiral Bronsted base catalysis is addressed. The recent efforts to overcome this challenge and broaden the range of viable enantioselective transformations are summarized, focusing on the development and application of two types of chiral organosuperbase catalyst.
Article
Chemistry, Organic
Xilong Wang, Yu Luo, Jiaji Zhao, Shuang Luo
Summary: A highly selective enantio- and diastereoselective domino thia-Michael/aldol reaction has been developed using 5H-dibenzo[a,c][7]annulen-5-one as a Michael acceptor and catalyzed by a chiral phosphoric acid (CPA). The resulting bridged biaryl adduct contains multiple stereogenic centers in the bridging linkage and a thermodynamically controlled stereogenic axis. The observed excellent diastereoselectivity (>20 : 1) can be explained by an energy difference of about 9.1 kcal mol (-1) between the two atropodiastereomers.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Stuart C. D. Kennington, Saul F. Teloxa, Miguel Mellado-Hidalgo, Oriol Galeote, Sabrina Puddu, Marina Bellido, Pedro Romea, Felix Urpi, Gabriel Aullon, Merce Font-Bardia
Summary: A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes was reported. The reaction gives high yields of O-TIPS-protected anti-aldol adducts with remarkable stereocontrol and atom economy. The removal of the achiral scaffold provides enantiomerically pure intermediates with synthetic interest for producing anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives, with theoretical calculations explaining the observed high stereocontrol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Masaru Kondo, Kento Nakamura, Chandu G. Krishnan, Hiroaki Sasai, Shinobu Takizawa
Summary: This study presents recent advances in photoswitchable chiral organocatalysts and their applications in the photomodulation of enantioselective reactions. Under appropriate light irradiation, the E/Z-photoisomerization of the photoresponsive units on the catalysts controls the catalytic activity and/or selectivity of the reactions. The study also elucidates the design, synthesis, and catalytic application of azobenzene BINOL-based photoswitchable chiral phase-transfer catalysts. This account provides insights into the appropriate design of a photoswitchable chiral organocatalyst for achieving good enantioselectivity and photocontrol.
Article
Chemistry, Organic
Shinya Adachi, Akira Saito, Masakatsu Shibasaki
Summary: This study reports a method for direct catalytic asymmetric reactions of alkylnitriles and imines. By adding specific catalysts and additives, high yields, high anti/syn diastereoselectivities, and high enantiomeric ratios can be achieved.
Article
Chemistry, Organic
Ying Zou, Chen-Yi Li, Min Xiang, Wen-Sheng Li, Jian Zhang, Wen-Juan Wan, Li-Xin Wang
Summary: The evaluation of a new scaffold organocatalyst shows excellent yields and good enantioselectivities in the enantioselective aldol condensation. The steric control plays a more important role in determining the enantioselectivity compared to amide NAH hydrogen bonding.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Physical
Masaru Kondo, Kento Nakamura, Chandu G. Krishnan, Shinobu Takizawa, Tsukasa Abe, Hiroaki Sasai
Summary: The Azo-crown ether-based photoswitching chiral phase transfer catalysts control catalytic activity through structural transformation induced by E/Z photoisomerization. This allows for promotion or hindrance of the enantioselective alkylation of glycine Schiff base to yield chiral amino acid derivatives.
Article
Materials Science, Multidisciplinary
Xiaojing Yu, Qiong Wu, Zhongxin Jin, Jianjiao Xin, Haijun Pang, Huiyuan Ma, Xinming Wang, Lichao Tan, Guixin Yang
Summary: A new polyoxometalate-based silver-organic framework has been synthesized and shows efficient catalytic activity in the cyanosilylation reaction, demonstrating significant potential for practical applications.
MATERIALS TODAY COMMUNICATIONS
(2022)
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.
Review
Chemistry, Organic
Li Xin, Song Qiuling
Summary: Chiral boranes have emerged as privileged catalysts in asymmetric reactions due to their lower catalyst loading and easier access compared to chiral transition metal catalysts. This article summarizes and discusses the chiral borane-catalyzed enantioselective reactions, organized into three parts based on reaction categories.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Naveen Diddi, Dale E. Ward
Summary: The total synthesis of dolabriferol C was achieved by a series of unique chemical reactions, simplifying the synthetic process significantly. This synthetic approach combines different stereochemical selectivities and enantioselective reactions, providing new insights for the study of related compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Mangala Gowri Ponnapalli, Nalini Dangeti, Madhu Babu Sura, Haribabu Kothapalli, V. S. Sarma Akella, Jeelani Basha Shaik
NATURAL PRODUCT RESEARCH
(2017)
Article
Chemistry, Inorganic & Nuclear
Togapur Pavan Kumar, Sthanikam Siva Prasad, Kothapalli Haribabu, Veerjala Naveen Kumar, Cirandur Suresh Reddy
TETRAHEDRON-ASYMMETRY
(2016)
Article
Chemistry, Inorganic & Nuclear
Togapur Pavan Kumar, Mohammad Abdul Sattar, Sthanikam Siva Prasad, Kothapalli Haribabu, Cirandur Suresh Reddy
TETRAHEDRON-ASYMMETRY
(2017)
Article
Chemistry, Medicinal
Boddu Shashi Kanth, Avula Satya Kumar, Digambar Balaji Shinde, Kothapalli Hari Babu, Tuniki Venugopal Raju, Chityal Ganesh Kumar, Pombala Sujitha, Biswanath Das
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2011)
Article
Chemistry, Medicinal
Vidadala Ramasubba Rao, Puppala Muthenna, Gundeti Shankaraiah, Chandrasekhar Akileshwari, Kothapalli Han Babu, Ganji Suresh, Katragadda Suresh Babu, Rotte Sateesh Chandra Kumar, Kothakonda Rajendra Prasad, Potharaju Ashok Yadav, J. Mark Petrash, Geereddy Bhanuprakash Reddy, Janaswamy Madhusudana Rao
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2012)
Article
Chemistry, Organic
Chada Raji Reddy, Motatipally Damoder Reddy, Kothapalli Haribabu
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2012)
Article
Chemistry, Analytical
Kothapalli Haribabu, Makula Ajitha, Bokka Ramesh, Katragadda Suresh Babu, Janaswamy Madhusudana Rao
JPC-JOURNAL OF PLANAR CHROMATOGRAPHY-MODERN TLC
(2012)
Article
Chemistry, Applied
Vidadala Rama Subba Rao, Sagi Satyanarayana Raju, Vanka Umamaheswara Sarma, Fouriner Sabine, Kothapalli Hari Babu, Katragadda Suresh Babu, Janaswamy Madhusudana Rao
NATURAL PRODUCT RESEARCH
(2011)
Article
Chemistry, Inorganic & Nuclear
Srivari Chandrasekhar, Togapur Pavan Kumar, Kothapalli Haribabu, Chada Raji Reddy, Chitumalla Ramesh Kumar
TETRAHEDRON-ASYMMETRY
(2011)
Article
Chemistry, Inorganic & Nuclear
Togapur Pavan Kumar, Kothapalli Haribabu
TETRAHEDRON-ASYMMETRY
(2014)
Article
Chemistry, Inorganic & Nuclear
Tumma Naresh, Togapur Pavan Kumar, Kothapalli Haribabu, Srivari Chandrasekhar
TETRAHEDRON-ASYMMETRY
(2014)
Article
Chemistry, Inorganic & Nuclear
Togapur Pavan Kumar, Laghuvarapu Radhika, Kothapalli Haribabu, Veerjala Naveen Kumar
TETRAHEDRON-ASYMMETRY
(2014)
Article
Chemistry, Multidisciplinary
Srivari Chandrasekhar, Chintakunta Praveen Kumar, Togapur Pavan Kumar, Kothapalli Haribabu, Bharatam Jagadeesh, Jerripothula K. Lakshmi, Prathama S. Mainkar
Article
Biochemical Research Methods
Bokka Ramesh, Sisla Ramakrishna, Rentam Kiran Kumar Reddy, Kothapalli Hari Babu, Vanka Uma Maheswara Sarma, Potturi Sita Devi
JOURNAL OF LIQUID CHROMATOGRAPHY & RELATED TECHNOLOGIES
(2013)
