Article
Chemistry, Organic
Anilkumar Gunnam, Alagesan Balasubramani, Goverdhan Mehta
Summary: The recursive anion-mediated activation of o-bis-ynones leads to the one-pot synthesis of 1-indenones, and further reactions result in the access to the embellished cyclopenta[a]inden-8(2H)-one core and its spiroannulated analogues.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Xiaoqing Song, Ruizhi Wang, Liang Shi, Tianlong Luo, Zhiyu Gao, Li Ren, Wenming Zhou, Hong-Dong Hao
Summary: An isochromene synthesis method was developed using a cascade reaction involving a CuI catalyzed coupling reaction, allenoate isomerization, and subsequent oxa-Michael addition. The cascade sequence was also demonstrated for the synthesis of naphthalenes, and applied toward a stereoselective synthesis of pyranonaphthoquinone kalafungin.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Jian-Bin Lu, Chong-Hui Shi, Di Hu, Xin-Yue Gao, Zhi-Chao Chen, Wei Du, Ying-Chun Chen
Summary: The research demonstrates that cinnamates with an ortho-formyl group can undergo specific reactions with dienals under the catalysis of chiral amines, ultimately leading to the formation of polyhydrophenanthrene frameworks with excellent diastereo- and enantioselectivity.
Article
Chemistry, Organic
Pavel K. Elkin, Nathaniel D. Durfee, Viresh H. Rawal
Summary: The study explores the cycloaddition reactions of 1-alkoxy-1-amino-1,3-butadienes, which are prepared from crotonic acid chloride and its derivatives. These doubly activated dienes react with electron-deficient dienophiles to form cycloadducts under mild conditions, providing versatile building blocks for complex molecule synthesis. Hydrolysis of the DA cycloadducts yields 6-substituted and 6,6-disubstituted 2-cylohexenones, while the corresponding HDA cycloadducts afford 6-substituted 5,6-dihydropyran-2-ones.
Article
Chemistry, Physical
Dixita Rani, Vinny Gulati, Mamta Guleria, Satya Prakash Singh, Jyoti Agarwal
Summary: An efficient and aqueous protocol for the synthesis of 2-aryl-3-nitro-2H-chromene derivatives has been developed. The protocol involves the L-prolinamide mediated tandem oxa-Michael Henry reaction, and excellent yields are obtained in water.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Organic
Dongping Cheng, Xianhang Yan, Yueqi Pu, Jing Shen, Xiaoliang Xu, Jizhong Yan
Summary: An efficient tandem oxidative annulation for the synthesis of 2,2-disubstituted 2,3-dihydroquinazolin-4(1H)-ones via DDQ-mediated dual cross-dehydrogenative-coupling (CDC) reactions is described, resulting in moderate to excellent yields of the corresponding products.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Hengqian Song, Jiacheng Song, Lihong Yan, Weigang He, Pengyan Wang, Yuanzhen Xu, Hongbo Wei, Weiqing Xie
Summary: The asymmetric synthesis of (-)-dihydrospirotryprostatin B has been achieved in 8 longest linear steps from commercially available amino acids. The key step involves the tandem Michael addition of oxindole derived from dipeptide diketopiperazine to alkynone, leading to the rapid construction of the spiro [pyrrolidine-3,3'-oxindole] scaffold.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Organic
Sadhanendu Samanta, Jin Cui, Hidetoshi Noda, Takumi Watanabe, Masakatsu Shibasaki
Summary: In this study, a gram-scale syn-selective asymmetric vinylogous addition of butenolides to chromones was developed using an Al-Li-BINOL (ALB) complex catalyst. The reaction showed high diastereoselectivity with ratios up to 20:1 and enantioselectivity of 84-98% for various substrate combinations. This method is complementary to previous reports and improves selectivity for several chromones. Computational studies support the role of ALB as a bifunctional catalyst in this reaction and provide insights into the origin of the observed stereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sadhanendu Samanta, Jin Cui, Hidetoshi Noda, Takumi Watanabe, Masakatsu Shibasaki
Summary: A gram-scale syn-selective asymmetric vinylogous addition of butenolides to chromones, catalyzed by an Al-Li-BINOL (ALB) complex, was developed in this study. The diastereoselectivity reached 20:1 with 84-98% ee for various combinations of substrates. This protocol complements previous methods and improves selectivity for multiple chromones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Domenico C. M. Albanese, Nicoletta Gaggero, Kamila Prenga
Summary: 3,4-dihydropyridin-2-ones are important due to their diverse biological and pharmacological activities. This study presents a practical reaction cascade for the synthesis of various substituted 3,4-dihydropyridin-2-ones through the Michael-type addition of 1,3-dithiane-2-carbothioates to alpha,beta-unsaturated N-tosyl imines, followed by intramolecular annulation. The reaction was carried out using solid-liquid phase transfer catalysis (SL-PTC) conditions at room temperature, with short reaction times and the use of inexpensive catalysts. It is a green and reliable method that can be easily scaled up from readily available starting materials.
Article
Chemistry, Organic
Abhilash Sharma, Hemanta Hazarika, Pranjal Gogoi
Summary: In recent years, o-quinone methides and o-quinone sulfides have been widely recognized as reactive intermediates in the synthesis of diversely functionalized ortho-disubstituted arenes and heterocycles. This synopsis provides a comprehensive overview on the potential applications of these compounds in the one-pot synthesis of ortho-disubstituted arenes and heterocycles via arynes, highlighting their importance in organic synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Lorenzo Serusi, Laura Palombi, Giovanni Pierri, Antonia Di Mola, Antonio Massa
Summary: The asymmetric synthesis of novel 3-substitued isoindolinones was achieved using the asymmetric nitro-Mannich reaction and the in situ cyclization reaction. High enantioselectivities and yields were obtained in the presence of a neutral bifunctional organocatalyst. The investigation of the reactivity of the obtained products also revealed the potential for further functionalization.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Subhash P. Chavan, Dinesh B. Kalbhor, Rajesh G. Gonnade
Summary: A synthesis of 2-epi-biotin sulfone was achieved from commercially available L-cysteine, involving a tandem S,N-carbonyl migration/aza-Michael/spirocyclization reaction and a late-stage Haller-Bauer reaction for diastereoselective carbon side chain introduction.
Review
Biochemistry & Molecular Biology
Camilo Morales-Manrique, Edwin A. Baquero, James Guevara-Pulido
Summary: In recent years, N-heterocyclic carbenes (NHCs) have been recognized as versatile organocatalysts for the activation of aldehydes, leading to the production of 3,4-dihydropyran-2-ones and related derivatives. This review provides an overview of the organocatalytic processes involving NHCs in synthesizing these compounds over the past eight years. These processes utilize various substrates, catalysts, and reaction conditions, mainly focusing on [4+2] and [3+3] cycloadditions to generate the desired skeleton with biological activity and multiple stereocenters. The resulting products can be scaled up and further modified for potential applications in the field of biology.
Article
Chemistry, Organic
Pankaj Khairnar, Yin-Hsiang Su, Athukuri Edukondalu, Wenwei Lin
Summary: An enantioselective synthesis of spiropyrazolone-fused cyclopenta[c]chromen-4-ones is demonstrated via a (3+2) cycloaddition reaction using cinchona-alkaloid derived hydrogen-bonding catalyst. The method provides high yields of adducts with five contiguous stereocenters, including a spiro all-carbon quaternary stereocenter with good to excellent stereoselectivities. The one-pot methodology can also be scaled up effectively.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
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)
