Article
Chemistry, Organic
Matthew R. Nelli, Rachel L. Cantrell, Ryan E. Looper
Summary: A successful gold-catalyzed hydroamination of yneamide tethered amines revealed strategies to access the 1,4-diazepindiones heterocyclic core of the TAN-1057 family of natural products. The precursor amino-yneamides, derived from easily accessible 1,2-diamines and alkynoic acids, are efficiently cyclized to the corresponding diazepineones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Jiayue Fu, Bingbing Li, Zefang Zhou, Maosheng Cheng, Lu Yang, Yongxiang Liu
Summary: The formal total synthesis of macarpine was achieved by constructing a naphthol intermediate using two different synthetic routes in Ishikawa's synthetic route. The convergent synthetic strategies involved the use of Au(I)-catalyzed cycloisomerization reactions of 1,5-enyne and alkynyl ketone substrates prepared via Sonogashira coupling reactions.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Santosh J. Gharpure, Raj K. Patel, Krishna S. Gupta
Summary: Stereoselective syntheses of pyrrolidines and piperidines bearing hydrophobic chains were achieved through a metal-free, Lewis acid-mediated 5/6-endo-dig reductive hydroamination cascade of enynyl amines. The developed strategy allowed for the collective stereoselective total synthesis of various alkaloids, including (& PLUSMN;)-pyrrolidine cis-225H, (& PLUSMN;)-epi-197B, (& PLUSMN;)-epi-225C, the family of (+)-solenopsins and (+)-isosolenopsins, and the formal synthesis of (& PLUSMN;)-bgugaine and (+)-azimic acid.
Article
Chemistry, Organic
Gottam Sreenivasulu, Balasubramanian Sridhar, Galla V. Karunakar
Summary: An efficient method has been developed for the regioselective synthesis of benzofulvenes using dual gold catalysis from substituted allyloxy 1,5-diynes via 5-endo dig cyclization. A new C-C bond formation occurs in this intramolecular organic transformation, resulting in moderate to very good yields in one pot.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Gottam Sreenivasulu, Balasubramanian Sridhar, Galla V. Karunakar
Summary: An efficient dual gold-catalyzed regioselective synthesis of benzofulvenes has been developed from substituted allyloxy 1,5-diynes via 5-endo dig cyclization, resulting in moderate to very good yields in one pot.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Diego Sorbelli, Jacopo Segato, Alessandro Del Zotto, Leonardo Belpassi, Daniele Zuccaccia, Paola Belanzoni
Summary: A computational mechanistic study aimed to rationalize the experimental counterion- and solvent-dependent reactivity in the gold(I)-catalyzed Meyer-Schuster rearrangement of 1-phenyl-2-propyn-1-ol, revealing the unexpected formation of a gold-oxetene intermediate through commonly unfavorable 4-endo-dig cyclization triggered by the counterion in low polarity solvents.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Gottam Sreenivasulu, Veerabhushanam Kadiyala, Chittala Emmaniel Raju, Balasubramanian Sridhar, Galla Karunakar
Summary: An efficient gold-catalyzed synthesis of pyrazolo[1,5-a]pyridines has been developed from pyrazolo substituted propargyl alcohols via 6-endo-dig cyclization. In this intramolecular cyclization reaction, a new C-N bond was regioselectively formed, and good to excellent yields of pyrazolo[1,5-a]pyridines were obtained in one-pot.
Article
Chemistry, Organic
Mamoru Ito, Asahi Takaki, Moeka Okamura, Kyalo Stephen Kanyiva, Takanori Shibata
Summary: The study developed gold-catalyzed 7-exo- and 8-endo-dig-selective cycloisomerizations, providing different compounds based on the nucleophilicity and electron-withdrawing effect during the reactions. Additionally, the method could be extended to ynamide substrates with silver-catalyzed reactions yielding 7-exo-dig products selectively.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Chanhyun Jung, Siyuan Li, Kwanghee Lee, Mayavan Viji, Heesoon Lee, Soonsil Hyun, Kiho Lee, Young Kee Kang, Chhabi Lal Chaudhary, Jae-Kyung Jung
Summary: In this study, solvent-directed intramolecular hydrofunctionalization of readily available o-alkynoylphenols was successfully achieved under reagent-free conditions. The strategy is remarkable for its regioselectivity, atom economy, and efficiency in terms of atom, carbon, and reaction mass.
Article
Chemistry, Applied
Romeric Galea, Gaelle Blond
Summary: In this study, [7,5]-fused bicyclic acetals, also known as furooxepines, were synthesized through a gold(I)-catalyzed domino reaction. This one-step reaction allows the formation of multiple bonds, heterocycles, and a tetrasubstituted carbon stereocenter with 100% atom economy.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Souta Misawa, Asaki Miyairi, Yoshihiro Oonishi, Steven P. Nolan, Yoshihiro Sato
Summary: Polarized alkynes such as ynol ethers and ynamides undergo Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reactions with allylic alcohols, proceeding under mild conditions with high regioselectivity. The resulting gamma,delta-unsaturated esters or amides are formed in an atom-economical manner using the [Au(IPr)NTf(2)] catalyst.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Tatiana Suarez-Rodriguez, Angel L. Suarez-Sobrino, Alfredo Ballesteros
Summary: Gold(I)-catalyzed higher-order [8+2] cycloadditions of 8-aryl-8-azaheptafulvenes with allenamides and ynamides were studied, resulting in the formation of 1,8-dihydrocycloheptapyrroles and 2-amido-1,4-dihydrocycloheptapyrroles, respectively. The reactions proceeded with good yields and various substituents, suggesting a nucleophilic attack mechanism involving the gold-activated electron-rich moieties of the allenamide and ynamide.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Tales A. C. Goulart, Davi Fernando Back, Sidnei Moura E. Silva, Gilson Zeni
Summary: The selective synthesis of 4-alkynyloxazolones and their application as substrates for electrophile-promoted nucleophilic cyclization were developed. The reaction of ynamides with terminal alkynes in the presence of a palladium(II) acetate catalyst resulted in the smooth formation of 4-alkynyloxazolones. The products were obtained through a cascade reaction involving the formation of new C-C and C-O bonds. The 4-alkynyloxazolones further reacted with an electrophilic selenium source to yield 3-phenylselanyl benzofuran derivatives through electrophile-promoted nucleophilic cyclization.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Purnachandar Dalovai, Galla Venkata Karunakar, Vidya Damodaran Nadar, Venkata Ramana Doddi, Suneel Kanaparthy
Summary: An efficient synthetic method for accessing substituted aminobenzophenones has been developed, catalyzed by gold and forming a new C-C bond through intramolecular 6-endo-dig cyclization. The substituted aminobenzophenones were obtained in good to excellent yields.
JOURNAL OF CHEMICAL SCIENCES
(2021)
Article
Chemistry, Organic
Nabakumar Bera, Bhabani Sankar Lenka, Sangita Bishi, Shantanu Samanta, Debayan Sarkar
Summary: A new mechanistic pathway of propargylic alcohol activation by gold(I) catalysis has been proposed, which efficiently synthesizes pyrroles, pyridinones, and indoles. Control experiments confirm the formation of an allene oxide intermediate through the participation of the oxygen atom of propargylic alcohol, and this method is successfully applied to the synthesis of hydroxyalkyl indoles and benzofurans.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
