Rhodium‐Catalyzed CH Functionalization to Construct Annulated Molecules DOI
Sujit Mahato, Writhabrata Sarkar, Koushik Naskar

et al.

Handbook of CH‐Functionalization, Journal Year: 2022, Volume and Issue: unknown, P. 1 - 39

Published: Oct. 2, 2022

Abstract Rhodium complexes are exceptionally significant in homogeneous catalysis. The synthetic community observed the rapid burgeoning of such rhodium catalysis since discovery Wilkinson's catalyst. Rhodium‐catalyzed tandem C(sp 2 )H/C(sp 3 )H activation and annulation with alkenes, alkynes, arenes, other reactive partners is a rapidly growing research field to obtain new class heterocycles thereby generates potential biologically active pharmacophores. Superior reactivity catalysts attributed due its good π‐acceptor character that favors CH bond reaction substrates containing wide range directing groups, as amides, imines, carboxylic acid (derivatives), benzylic alcohols, ketones, various shown efficiency toward befitting partners; even undirected activations have also been achieved. This article provides brief account recent developments rhodium‐catalyzed activation/annulation reactions for synthesis classes fused cyclic scaffolds using suitable coupling partners. For strategies, different types cyclization reactions, namely, oxidative, redox‐neutral, photoredox, electrochemical discussed. In addition, enantioselective annulated molecules chiral has highlighted.

Language: Английский

Rhodium‐Catalyzed Dual C−H Activation for Regioselective Triple Annulation of Enaminones: Access to Polycyclic Naphthopyran Derivatives DOI

V. Suresh,

Muniganti Naveen Kumar,

Attunuri Nagireddy

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(11), P. 1770 - 1776

Published: March 21, 2023

Abstract Rh‐catalyzed C−H activation of arenes for oxidative annulations with alkynes stands out as a protocol polycyclic scaffolds. This perspective drives us to disclose herein rhodium catalyzed regioselective triple annulation enaminones hydroxyl‐alkynoates via double functionalization naphtho‐pyran Secondary coordination OH in alkynoate dictated the regioselectivity. Initial lactonization occurred chemoselectively on enamine part carbo rhodation followed by reductive elimination. was scalable and has shown high functionality tolerance. KIE studies were done get insight mechanism, some downstream transformations achieved show synthetic potential method.

Language: Английский

Citations

16
Recent Progress in Application of Propargylic Alcohols in Organic Syntheses DOI
Fatemeh Doraghi,

Amir Mohammad Mahdavian,

Somaye Karimian

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(18), P. 2991 - 3019

Published: July 14, 2023

Abstract Propargylic alcohols are readily available bifunctional (alkyne and hydroxyl groups) synthons, which recognize as one of the attractive synthetic feedstock in organic transformations. Especially, recent years employment these valuable molecules has frequently been observed literature. Hence, present review highlights advancements application propargylic cyclization, substitution, addition reactions.

Language: Английский

Citations

15
Rhodium-Catalyzed Regioselective Double Annulation of Enaminones with Propargyl Alcohols: Rapid Access to Arylnapthalene Lignan Derivatives DOI
Attunuri Nagireddy,

Dattatri,

Ramesh Kotipalli

et al.

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 87(2), P. 1240 - 1248

Published: Dec. 29, 2021

We present here a rhodium-catalyzed oxidative three-point double annulation of enaminones with propargylic alcohols via C–H and C–N bond activation to access arylnaphthalene-based lignan derivatives. The key step in the reaction is regioselective insertion alcohol into rhoda-cycle, result hydroxyl rhodium coordination. Necessary control experiments KIE studies were conducted determine mechanism.

Language: Английский

Citations

29
Silver‐Free C−H Activation: Strategic Approaches towards Realizing the Full Potential of C−H Activation in Sustainable Organic Synthesis DOI Creative Commons
Arup Mondal, Manuel van Gemmeren

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(48)

Published: Sept. 5, 2022

The activation of carbon-hydrogen bonds is considered as one the most attractive techniques in synthetic organic chemistry because it bears potential to shorten routes well produce complementary product scopes compared traditional strategies. However, many current methods employ silver salts additives, leading stoichiometric metal waste and thereby preventing full C-H be exploited. Therefore, development silver-free protocols has recently received increasing attention. Mechanistically, can serve various roles thus, avoiding use requires different approaches based on role serves a given process. In this Review, we present comparison silver-based methods. Focusing strategic develop activation, provide reader with means sustainable for activation.

Language: Английский

Citations

21
Rh(III)-Catalyzed annulative aldehydic C-H functionalization for accessing ring-fluorinated benzo[b]azepin-5-ones DOI

Qiuyun Li,

Kelu Yan, Yannan Zhu

et al.

Chinese Chemical Letters, Journal Year: 2022, Volume and Issue: 34(6), P. 108014 - 108014

Published: Nov. 23, 2022

Language: Английский

Citations

20
Pd-catalyzed regioselective rollover dual C–H annulation cascade: facile approach to phenanthrene derivatives DOI

Muniganti Naveen Kumar,

V. Suresh,

Attunuri Nagireddy

et al.

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(64), P. 9714 - 9717

Published: Jan. 1, 2023

A Pd-catalyzed rollover cascade dual C–H annulation of aryl phenols with alkynols for producing phenanthrene scaffolds in a regioselective manner was developed. Necessary control, KIE and deuterium experiments were conducted to determine the reaction mechanism.

Language: Английский

Citations

11
Steglich’s Base Catalyzed Three-Component Synthesis of Isoxazol-5-Ones DOI

Zeinab Faramarzi,

Hamzeh Kiyani

Polycyclic aromatic compounds, Journal Year: 2022, Volume and Issue: 43(4), P. 3099 - 3121

Published: April 7, 2022

4-(Dimethylamino)pyridine (DMAP) has been used as an efficient Brønsted organo-base catalyst for the one-pot, three-component cyclization of various aldehydes, β-keto esters, and hydroxylamine hydrochloride. In this organocatalyzed reaction, 3,4-disubstituted isoxazole-5(4H)-ones were efficiently formed in high yields relatively shorter reaction times. Using 8 mol% DMAP, a mixture water–ethanol solvent system, 80 °C gave best results. The heterocyclization using arylaldehydes containing electron releasing groups is well performed heterocyclic products obtained good to isolated yields. Aldehydes with withdrawing did not lead formation products. This method many advantages such broad substituent scope, mild eco‐friendly conditions, step atom economy, commercially available, inexpensive organo-basic catalyst.

Language: Английский

Citations

18
Recent approaches for the synthesis of pyridines and (iso)quinolines using propargylic Alcohols DOI

Surabhi Mishra,

Sindoori R. Nair,

Beeraiah Baire

et al.

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(31), P. 6037 - 6056

Published: Jan. 1, 2022

This review article contains various synthetic strategies for the generation of pyridines, quinolines, and isoquinolines from propargylic alcohols during period between 2005–2021. is first focused that has appeared on this topic.

Language: Английский

Citations

17
Rhodium-Catalyzed Coordination-Assisted Regioselective and Migratory Three-Point Double Annulation of o-Alkenyl Phenols with Tertiary Propargyl Alcohols DOI
Attunuri Nagireddy,

Ramesh Kotipalli,

Jagadeesh Babu Nanubolu

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(28), P. 5062 - 5067

Published: July 11, 2022

We disclose herein a Rh(III)-catalyzed migratory three-point double annulation of o-alkenyl phenols with propargyl alcohols for de novo construction naphtho furan derivatives in regio- and chemoselective manner. The protocol orchestrates two new rings four bonds one operation without the need any additive. Necessary labeled control experiments are conducted to elucidate reaction mechanism. A tertiary hydroxyl group is found be crucial both controlling regioselective insertion alkyne through chelation rhodium form key spiro cyclic intermediate forcing ring expansion via unusual selective olefin reshuffling, apart from forming an extra (furan) ring. scalable shows tolerance late stage functionalization natural products.

Language: Английский

Citations

17
Pd-Catalyzed Chelation-Assisted Regioselective and Site Selective Cyclative C–H Annulation of Alkynyl Oximes with Activated Alkynes DOI

Ramesh Kotipalli,

Jagadeesh Babu Nanubolu, Maddi Sridhar Reddy

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(6), P. 3834 - 3843

Published: Feb. 29, 2024

Electrophilic cyclization and concomitant C–H annulation constitute an expedient cascade strategy for the construction of multicyclic scaffolds with precise substitutional patterns. We report here a novel Pd-catalyzed cyclative ynone oxime activated alkynes. The features dual regioselectivity including site selective activation chelation-assisted insertion Control experiments together kinetic give insights into mechanism.

Language: Английский

Citations

3