Rh-Catalyzed C–H activation/intramolecular condensation for the construction of benzo[f]pyrazolo[1,5-a][1,3]diazepines

2020 ◽  
Vol 18 (15) ◽  
pp. 2893-2901 ◽  
Author(s):  
Yi Ning ◽  
Xinwei He ◽  
Youpeng Zuo ◽  
Jian Wang ◽  
Qiang Tang ◽  
...  
Keyword(s):  
Intramolecular Condensation

A novel and mild Rh(iii)-catalyzed cascade C–H activation/intramolecular condensation of 1-aryl-1H-pyrazol-5-amines with cyclic 2-diazo-1,3-diketones for the synthesis of various important benzo[f]pyrazolo[1,5-a][1,3]diazepines has been developed.

scholarly journals One-Pot Synthesis of Novel Multisubstituted 1-Alkoxyindoles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1466
Author(s):  
Ye Eun Kim ◽  
Hyunsung Cho ◽  
Yoo Jin Lim ◽  
Chorong Kim ◽  
Sang Hyup Lee
Keyword(s):  
Alkyl Halide ◽  
The Novel ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Consecutive Reactions ◽  
Intramolecular Condensation ◽  
Synthetic Sequence ◽  
Novel Target

Studies on a one-pot synthesis of novel multisubstituted 1-alkoxyindoles 1 and their mechanistic investigations are presented. The synthesis of 1 was successfully achieved through consecutive four step reactions from substrates 2. The substrates 2, prepared through a two-step synthetic sequence, underwent three consecutive reactions of nitro reduction, intramolecular condensation, and nucleophilic 1,5-addition to provide the intermediates, 1-hydroxyindoles 8, which then were alkylated in situ with alkyl halide to afford the novel target products 1. We optimized the reaction conditions for 1 focusing on the alkylation step, along with the consideration of formation of intermediates 8. The optimized condition was SnCl2·2H2O (3.3 eq) and alcohols (R1OH, 2.0 eq) for 1–2 h at 40 °C and then, base (10 eq) and alkyl halides (R2Y, 2.0 eq) for 1–4 h at 25–50 °C. Notably, all four step reactions were performed in one-pot to give 1 in good to modest yields. Furthermore, the mechanistic aspects were also discussed regarding the reaction pathways and the formation of side products. The significance lies in development of efficient one-pot reactions and in generation of new 1-alkoxyindoles.

A Domino Heck Coupling–Cyclization–Dehydrogenative Strategy for the One-Pot Synthesis of Quinolines

Synthesis ◽  
2021 ◽  
Author(s):  
Santanu Ghora ◽  
Chinnabattigalla Sreenivasulu ◽  
Gedu Satyanarayana
Keyword(s):  
Functional Group ◽  
Exchange Process ◽  
Palladium Catalysis ◽  
Allylic Alcohols ◽  
Heck Coupling ◽  
One Pot ◽  
Synthetic Process ◽  
Intramolecular Condensation ◽  
The One

AbstractAn efficient, one-pot, domino synthesis of quinolines via the coupling of iodoanilines with allylic alcohols facilitated by palladium catalysis is described. The overall synthetic process involves an intermolecular Heck coupling between 2-iodoanilines and allylic alcohols, intramolecular condensation of in situ generated ketones with an internal amine functional group, and a dehydrogenation sequence. Notably, this protocol occurs in water as a green solvent. Significantly, the method exhibits broad substrate scope and is applied for the synthesis of deuterated quinolines through a deuterium-exchange process.

Facile synthesis of 7–10 membered rings by intramolecular condensation using dialkylcarbonate as solvent

2004 ◽  
Vol 45 (51) ◽  
pp. 9335-9339 ◽  
Author(s):  
Tomomi Ikemoto ◽  
Tatsuya Ito ◽  
Atsuko Nishiguchi ◽  
Kiminori Tomimatsu
Keyword(s):  
Facile Synthesis ◽  
Intramolecular Condensation

scholarly journals Imaging and energetics of single SSB-ssDNA molecules reveal intramolecular condensation and insight into RecOR function

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jason C Bell ◽  
Bian Liu ◽  
Stephen C Kowalczykowski
Keyword(s):  
Long Range ◽  
Single Molecule ◽  
Magnetic Tweezers ◽  
Intramolecular Interactions ◽  
Ssdna Binding ◽  
Ssdna Binding Protein ◽  
Intramolecular Condensation ◽  
Nucleoprotein Complexes ◽  
Ssdna Binding Proteins ◽  
Dna Maintenance

Escherichia coli single-stranded DNA (ssDNA) binding protein (SSB) is the defining bacterial member of ssDNA binding proteins essential for DNA maintenance. SSB binds ssDNA with a variable footprint of ∼30–70 nucleotides, reflecting partial or full wrapping of ssDNA around a tetramer of SSB. We directly imaged single molecules of SSB-coated ssDNA using total internal reflection fluorescence (TIRF) microscopy and observed intramolecular condensation of nucleoprotein complexes exceeding expectations based on simple wrapping transitions. We further examined this unexpected property by single-molecule force spectroscopy using magnetic tweezers. In conditions favoring complete wrapping, SSB engages in long-range reversible intramolecular interactions resulting in condensation of the SSB-ssDNA complex. RecO and RecOR, which interact with SSB, further condensed the complex. Our data support the idea that RecOR--and possibly other SSB-interacting proteins—function(s) in part to alter long-range, macroscopic interactions between or throughout nucleoprotein complexes by microscopically altering wrapping and bridging distant sites.

Facile synthesis of chiral indolines through asymmetric hydrogenation of in situ generated indoles

2018 ◽  
Vol 5 (19) ◽  
pp. 2805-2809 ◽  
Author(s):  
Chang-Bin Yu ◽  
Jie Wang ◽  
Yong-Gui Zhou
Keyword(s):  
Asymmetric Hydrogenation ◽  
Hydrogenation Process ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Facile Synthesis ◽  
One Pot ◽  
Brönsted Acid ◽  
Palladium Catalyzed ◽  
Intramolecular Condensation

A concise synthesis of chiral indolines has been developed through intramolecular condensation, deprotection and palladium-catalyzed asymmetric hydrogenation in a one-pot process with up to 96% ee. A strong Brønsted acid played an important role in both the formation of indoles and asymmetric hydrogenation process.

scholarly journals Chemoselectivity-independent Cu-mediated coupling to construct the hydroquinoline skeleton of symbioimine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rie Fujita ◽  
Kengo Hanaya ◽  
Takeshi Sugai ◽  
Shuhei Higashibayashi
Keyword(s):  
Claisen Rearrangement ◽  
High Selectivity ◽  
Target Compound ◽  
Free Condition ◽  
Ligand Free ◽  
Intramolecular Condensation

AbstractConstruction of the hydroquinoline skeleton of symbioimine by Cu-mediated N-alkenylation or O-alkenylation of an allyl aminoalcohol, in which either chemoselectivity could lead to the target compound, was investigated. O-alkenylation followed by Claisen rearrangement was favored with high selectivity under a ligand-free condition. Subsequent intramolecular condensation furnished the hydroquinoline skeleton of symbioimine.

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