Iodine Catalyzed Synthesis of Substituted Furans and Pyrans: Reaction Scope and Mechanistic Insights DOI Creative Commons

Domenic Pace,

Raphaël Robidas, Uyen P. N. Tran

et al.

Published: July 6, 2020

Substituted pyrans and furans are core structures found in a wide variety of natural products biologically-active compounds. Herein, we report practical mild catalytic method for the synthesis substituted using molecular iodine, simple inexpensive catalyst. The described herein is performed solvent-free conditions ambient temperature atmosphere, thus offering facile green alternative to currently available reaction protocols. A combination experimental studies high‐level DFT calculations revealed interesting mechanistic insights this seemingly reaction.

Language: Английский

Selective Arene Hydrogenation for Direct Access to Saturated Carbo‐ and Heterocycles DOI Creative Commons
Mario P. Wiesenfeldt, Zackaria Nairoukh, Toryn Dalton

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(31), P. 10460 - 10476

Published: Jan. 31, 2019

Arene hydrogenation provides direct access to saturated carbo- and heterocycles thus its strategic application may be used shorten synthetic routes. This powerful transformation is widely applied in industry expected facilitate major breakthroughs the sciences. The ability overcome aromaticity while controlling diastereo-, enantio-, chemoselectivity central use of preparation complex molecules. In general, multisubstituted arenes yields predominantly cis isomer. Enantiocontrol imparted by chiral auxiliaries, Brønsted acids, or transition-metal catalysts. Recent studies have demonstrated that highly chemoselective transformations are possible. Such methods underlying strategies reviewed herein, with an emphasis on synthetically useful examples employ readily available

Language: Английский

Citations

249
Bimetallic Catalytic Asymmetric Tandem Reaction of β‐Alkynyl Ketones to Synthesize 6,6‐Spiroketals DOI
Shulin Ge, Weidi Cao, Tengfei Kang

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(12), P. 4017 - 4021

Published: Feb. 4, 2019

Abstract The enantioselective tandem reaction of β,γ‐unsaturated α‐ketoesters with β‐alkynyl ketones was realized by a bimetallic catalytic system achiral Au ΙΙΙ salt and chiral N , ′‐dioxide‐Mg ΙΙ complex. cycloisomerization ketone asymmetric intermolecular [4+2] cycloaddition subsequently occurred, providing an efficient straightforward access to multifunctional 6,6‐spiroketals in up 97 % yield, 94 ee >19/1 d.r. Besides, cycle proposed based on the results control experiments.

Language: Английский

Citations

83
Synthesis of Phenalenyl‐Fused Pyrylium Cations: Divergent C−H Activation/Annulation Reaction Sequence of Naphthalene Aldehydes with Alkynes DOI
Jiangliang Yin, Mei‐Ling Tan, Di Wu

et al.

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(42), P. 13094 - 13098

Published: Aug. 21, 2017

Abstract Described herein is the synthesis of stable oxonium‐doped polycyclic aromatic hydrocarbons (PAHs) by rhodium‐catalyzed C−H activation/annulations naphthalene‐type aldehydes with internal alkynes. This protocol provides four divergent reaction types, including two unexpected annulations an oxygen transposition process, which lead to diverse types phenalenyl‐fused pyrylium cations comprising a four‐, five‐, or six‐ring‐fused π‐conjugated core. The exhibit exquisite regioselectivity and high tolerance sensitive functional groups. These PAHs feature intriguing photophysical properties such as full‐color tunable fluorescence emission, quantum yield, positively charged core, can be reduced easily phenalenyl radicals.

Language: Английский

Citations

75
Interrupted Pyridine Hydrogenation: Asymmetric Synthesis of δ‐Lactams DOI

Tobias Wagener,

Lukas Lückemeier,

Constantin G. Daniliuc

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(12), P. 6425 - 6429

Published: Jan. 18, 2021

Abstract Metal‐catalyzed hydrogenation is an effective method to transform readily available arenes into saturated motifs, however, current strategies are limited the formation of C−H and N−H bonds. The stepwise addition hydrogen yields reactive unsaturated intermediates that rapidly reduced. In contrast, interruption complete by further functionalization offers great potential for increasing chemical complexity in a single reaction step. Overcoming tenet full reduction arene has been seldom demonstrated. this work we report synthesis sought‐after, enantioenriched δ‐lactams from oxazolidinone‐substituted pyridines water interrupted mechanism.

Language: Английский

Citations

42
Diastereo‐ and Enantioselective Synthesis of Bisbenzannulated Spiroketals and Spiroaminals by Ir/Ag/Acid Ternary Catalysis DOI
Wu‐Lin Yang,

Xin‐Yu Shang,

Tao Ni

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(42)

Published: Aug. 4, 2022

Abstract We reported herein an iridium/silver/acid ternary catalytic system to access bisbenzannulated [6,6]‐spiroketals in high efficiency with generally diastereo‐ and enantioselectivities (up >20 : 1 dr, >99 % ee). In this procedure, readily available o ‐alkynylacetophenones undergo cycloisomerization generate isochromenes situ that participate stereoselective allylation/spiroketalization sequence 2‐(1‐hydroxyallyl)phenols. Meanwhile, 2‐(1‐hydroxyallyl)anilines were also compatible cascade reaction, furnishing structurally novel [6,6]‐spiroaminals good diastereoselectivities (8 1–12 dr) excellent (98 %–>99 Moreover, experimental studies theoretical calculations performed illustrate the reaction mechanism stereochemistry.

Language: Английский

Citations

29
Die selektive Arenhydrierung bietet einen direkten Zugang zu gesättigten Carbo‐ und Heterocyclen DOI Creative Commons
Mario P. Wiesenfeldt, Zackaria Nairoukh, Toryn Dalton

et al.

Angewandte Chemie, Journal Year: 2019, Volume and Issue: 131(31), P. 10570 - 10586

Published: Jan. 31, 2019

Abstract Die Arenhydrierung bietet einen direkten Zugang zu gesättigten Carbo‐ und Heterocyclen kann daher zur Verkürzung von Synthesewegen genutzt werden. Diese nützliche Transformation wird industriell verwendet sollte weitere Durchbrüche in den angewandten Wissenschaften ermöglichen. Von zentraler Bedeutung für die Anwendung bei der Herstellung komplexer Moleküle ist Kontrolle Diastereo‐, Enantio‐ Chemoselektivität. Im Allgemeinen ergibt Hydrierung multisubstituierter Arene überwiegend das cis‐Isomer. Enantiokontrolle über chirale Auxiliare, Brønsted‐Säuren oder Übergangsmetallkatalysatoren erfolgen. Jüngere Arbeiten zeigen hoch chemoselektive Transformationen. Derartige Verfahren zugrunde liegenden Strategien werden hier erläutert, wobei Schwerpunkt auf präparativ nützlichen Reaktion mit leicht verfügbaren Katalysatoren liegt.

Citations

49
Rhodium‐Catalyzed Asymmetric Hydrogenation of 3‐Benzoylaminocoumarins for the Synthesis of Chiral 3‐Amino Dihydrocoumarins DOI
Yunnan Xu, Delong Liu, Yu Deng

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(44), P. 23602 - 23607

Published: Oct. 1, 2021

An asymmetric hydrogenation of 3-benzoylaminocoumarins was achieved for the first time using our BridgePhos-Rh catalytic system, providing chiral 3-amino dihydrocoumarins in high yields (up to 98 %) and with excellent enantioselectivities 99.7 % ee). The relationship between hydrogenations dihedral angles resulting π-π stacking effects complexes, which were determined by X-ray diffraction analysis, are discussed. corresponding hydrogenated products allow many transformations, several skeletons important physiological pharmacological activities.

Language: Английский

Citations

30
Enantioselective Hydrogenation of Imidazo[1,2‐a]pyridines DOI
Christoph Schlepphorst, Mario P. Wiesenfeldt, Frank Glorius

et al.

Chemistry - A European Journal, Journal Year: 2017, Volume and Issue: 24(2), P. 356 - 359

Published: Nov. 15, 2017

Abstract The enantioselective synthesis of tetrahydroimidazo[1,2‐ a ]pyridines by direct hydrogenation was achieved using ruthenium/N‐heterocyclic carbene (NHC) catalyst. reaction forgoes the need for protecting or activating groups, proceeds with complete regioselectivity, good to excellent yields, enantiomeric ratios up 98:2, and tolerates broad range functional groups. 5,6,7,8‐Tetrahydroimidazo[1,2‐ ]pyridines, which are found in numerous bioactive molecules, were directly obtained this method, its applicability demonstrated (formal) several molecules.

Language: Английский

Citations

36
A molybdate-incorporated cooperative catalyst: High efficiency in the assisted tandem catalytic synthesis of cyclic carbonates from CO2 and olefins DOI
Zhuolin Shi,

Guiqin Niu,

Qiuxia Han

et al.

Molecular Catalysis, Journal Year: 2018, Volume and Issue: 461, P. 10 - 18

Published: Oct. 10, 2018

Language: Английский

Citations

28
Bimetallic Catalytic Asymmetric Tandem Reaction of β‐Alkynyl Ketones to Synthesize 6,6‐Spiroketals DOI
Shulin Ge, Weidi Cao, Tengfei Kang

et al.

Angewandte Chemie, Journal Year: 2019, Volume and Issue: 131(12), P. 4057 - 4061

Published: Feb. 4, 2019

Abstract The enantioselective tandem reaction of β,γ‐unsaturated α‐ketoesters with β‐alkynyl ketones was realized by a bimetallic catalytic system achiral Au ΙΙΙ salt and chiral N , ′‐dioxide‐Mg ΙΙ complex. cycloisomerization ketone asymmetric intermolecular [4+2] cycloaddition subsequently occurred, providing an efficient straightforward access to multifunctional 6,6‐spiroketals in up 97 % yield, 94 ee >19/1 d.r. Besides, cycle proposed based on the results control experiments.

Language: Английский

Citations

26