Ynones in dearomative spirocyclisation processes; a review

Tetrahedron Chem, Journal Year: 2024, Volume and Issue: 9, P. 100055 - 100055

Published: Jan. 14, 2024

This review concentrates on our research into the discovery of novel ynone-based dearomative spirocyclisation processes, whilst placing new chemistry context existing knowledge. The genesis programme, development efficient synthetic routes to prepare natural products spirobacillene A (1) and B (2), utilised indole ynones. stimulated a much wider study explore reactivity ynones in processes more generally. Routes generate wide range spirocycles were subsequently developed, with reactions tethered indoles, benzofurans, benzisoxazoles, pyrroles, pyridines, isoquinolines, pyrazines, cyclic ketimines, anisoles all discussed herein, these initiated by catalytic Ag(I), Cu(II), Pd(0), photolysis many other reagents. Asymmetric variants some are also discussed, as is further elaboration spirocyclic give carbazoles, quinolones, polycycles useful building blocks. Finally, applications methodology product synthesis (e.g. A, lasubine II indolizidine 209D) described.

Language: Английский

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Intermolecular Allene–Alkyne Coupling: A Significantly Useful Synthetic Transformation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(10), P. 7814 - 7845

Published: May 6, 2024

Because of its wide applicability in the synthesis diverse unsaturated building blocks, allene–alkyne (AA) coupling has emerged as a powerful methodology to drive useful chemical transformations past two decades. Considering recent discoveries this active research area, Review, we aim support chemists selection suitable methods, particularly intermolecular approaches, according needs. However, inherent similarities between reactivities π-systems create considerable obstacles while predicting selectivity an platform. Therefore, herein, couplings for chemoselective, stereoselective, and regioselective syntheses acyclic cyclic C-skeletons are reviewed. considering lack well-organized review field, initially provide brief historical overview types thermally induced reactions that mostly feasible electronically biased components nonselective. Subsequently, emerging selective strategies described, which include activator-controlled neighboring functional group-assisted regio-, stereo-, π-skeleton-divergent processes. Overall, Review is divided into parts. In first part, fabrication explained reaction types. second synthetic affording structures reviewed based on substrate class (that is, nonassisted assisted substrates). Key intermediates each subset factors affecting product-selective discrimination species with highlight rationale systemically summarized. Understanding these structure- catalyst-dependent provides insights regulation chemoselectivities title AA cross-couplings and, therefore, design alternative catalytic routes distinct mechanistic features.

Language: Английский

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Dinuclear NHC–gold(i)–thiolato and –alkynyl complexes: synthesis, anticancer activity, and catalytic activity in lactonization reactions

Dalton Transactions, Journal Year: 2024, Volume and Issue: 53(18), P. 7939 - 7945

Published: Jan. 1, 2024

A series of novel dinuclear NHC–gold–thiolato and –alkynyl complexes bearing aromatic linkers were successfully synthesized by an efficient simple synthetic route.

Language: Английский

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Photosensitized Reductive Elimination of Gold(III) to Enable Esterification of Aryl Iodides with Carboxylic Acids

JACS Au, Journal Year: 2024, Volume and Issue: 4(8), P. 3084 - 3093

Published: July 25, 2024

Compared to the well-established transition metal-catalyzed cross-coupling reactions, Au(I)/Au(III)-catalyzed reactions have lagged behind. Despite some advancements, achieving gold-catalyzed C-O coupling with carboxylic acids via an Au(III) carboxylate intermediate remains challenging due thermal unfavorability of critical reductive elimination step. Here, we present first photosensitized gold(III) enable esterification aryl iodides acids. In presence a (P, N)-gold(I) catalyst and photosensitizer benzophenone under blue LED irradiation, derivatives were obtained from both alkyl (1°, 2°, 3°) Mechanistic modeling studies support that energy transfer (EnT) produces excited-state complex couples This photoinduced energy-transfer strategy has been applied in several other gold catalysis indicating its potential for further applications.

Language: Английский

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Gold-Catalyzed Skeletal Rearrangement of Alkenes: Regioselective Synthesis of Skeletally Diverse Tricyclic Heterocycles and Mechanistic Investigations

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(12), P. 6951 - 6959

Published: June 1, 2021

Transition metal-catalyzed skeletal rearrangement reactions have rapid advances in organic community. Their development benefits synthetic methodologies by providing versatile and flexible approaches toward special molecular scaffolds with high selectivity. Herein, a gold-catalyzed of alkenes alkynyl bromides is reported, enabling direct regioselective generation more than 50 examples skeletally diverse tricyclic heterocycles, namely, syn-tetrahydrocyclopenta[b]indoles benzofuro[3,2-b]pyridines, generally good yields. This protocol could tolerate terminal unactivated internal activated under air conditions, which hitherto unreported gold catalysis scarcely realized other reactions, thus opening avenues for the assembly heterocyclic systems efficiency. Aside from examining scope this rearrangement, mechanistic investigations to explain regioselectivity forming benzofuro[3,2-b]pyridines were conducted systematic theoretical calculations.

Language: Английский

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