PolyBorylated Alkenes as Energy‐Transfer Reactive Groups: Access to Multi‐Borylated Cyclobutanes Combined with Hydrogen Atom Transfer Event DOI Creative Commons
Nicole Hanania, Nadim Eghbarieh, Ahmad Masarwa

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(25)

Published: April 11, 2024

Abstract While polyborylated alkenes are being recognized for their elevated status as highly valuable reagents in modern organic synthesis, allowing efficient access to a diverse array of transformations, including the formation C−C and C‐heteroatom bonds, potential energy‐transfer reactive groups has remained unexplored. Yet, this holds key generating elusive biradical species, which can be captured by olefins, thereby leading construction new highly‐borylated scaffolds. Herein, we report designed strategy photosensitized [2+2]‐cycloadditions poly‐borylated with various olefins enabling regioselective synthesis cyclobutane motifs, 1,1‐di‐, 1,1,2‐tri‐, 1,1,2,2‐tetra‐borylated cyclobutanes. In fact, these compounds belong family that presently lacks synthetic pathways. Interestingly, when α‐methylstyrene was used, reaction involves an interesting 1,5‐hydrogen atom transfer (HAT). Mechanistic deuterium‐labeling studies have provided insight into outcome process. addition, cyclobutanes then demonstrated useful selective oxidation processes resulting cyclobutanones γ‐lactones.

Language: Английский

Access to Complex Scaffolds Through [2 + 2] Cycloadditions of Strained Cyclic Allenes DOI
Matthew McVeigh, Jacob P. Sorrentino,

Allison T. Hands

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 15420 - 15427

Published: May 20, 2024

We report the strain-induced [2 + 2] cycloadditions of cyclic allenes for assembly highly substituted cyclobutanes. By judicious choice trapping agent, complex scaffolds bearing heteroatoms, fused rings, contiguous stereocenters, spirocycles, and quaternary centers are ultimately accessible. Moreover, we show that resulting cycloadducts can undergo thermal isomerization. This study provides an alternative strategy to photochemical accessing functionalized cyclobutanes, while validating use underexplored strained intermediates architectures.

Language: Английский

Citations

6
Recent advances in the application of [2 + 2] cycloaddition in the chemical synthesis of cyclobutane-containing natural products DOI Creative Commons

Song-Yu Hou,

Bing‐Chao Yan,

Han-Dong Sun

et al.

Natural Products and Bioprospecting, Journal Year: 2024, Volume and Issue: 14(1)

Published: June 11, 2024

Abstract Cyclobutanes are distributed widely in a large class of natural products featuring diverse pharmaceutical activities and intricate structural frameworks. The [2 + 2] cycloaddition is unequivocally the primary most commonly used method for synthesizing cyclobutanes. In this review, we have summarized application with different reaction mechanisms chemical synthesis selected cyclobutane-containing over past decade. Graphical

Language: Английский

Citations

6
Photochemical [2+2] Cycloaddition of Alkynyl Boronates DOI Creative Commons
Oleksandr S. Liashuk, Oleksandr O. Grygorenko, Yulian M. Volovenko

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(54)

Published: July 3, 2023

Abstract A photochemical [2+2] cycloaddition of alkynyl boronates and maleimides is reported. The developed protocol provided 35–70 % yield maleimide‐derived cyclobutenyl demonstrated wide compatibility with various functional groups. synthetic utility the prepared building blocks was for a range transformations, including Suzuki cross‐coupling, catalytic or metal‐hydride reduction, oxidation, reactions. With aryl‐substituted boronates, products double were obtained predominantly. Using protocol, cyclobutene‐derived analogue Thalidomide in one step. Mechanistic studies supported participation triplet‐excited state ground key step process.

Language: Английский

Citations

13
Photosensitized [2 + 2]-Cycloadditions of Dioxaborole: Reactivity Enabled by Boron Ring Constraint Strategy DOI
Yanyao Liu, M. Kevin Brown

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(46), P. 25061 - 25067

Published: Nov. 8, 2023

A strategy to achieve photosensitized [2 + 2] cycloadditions by means of temporary ring constraint is reported. Specifically, a dioxaborole prepared that undergoes with wide variety alkenes. This overcomes some challenges the cycloaddition acyclic substrates. The products can be easily transformed into cyclobutyl diols or 1,4-dicarbonyl compounds; latter represents formal alkene vicinal diacylation. synthetic utility this method shown in synthesis valuable heterocycles and biatriosporin D.

Language: Английский

Citations

11
A Chemoselective Polarity‐Mismatched Photocatalytic C(sp3)−C(sp2) Cross‐Coupling Enabled by Synergistic Boron Activation** DOI Creative Commons

Jeremy Brals,

Thomas M. McGuire, Allan J. B. Watson

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(42)

Published: Aug. 25, 2023

We report the development of a C(sp

Language: Английский

Citations

10
Access to Azetidines via Gold Mediated Energy Transfer Photocatalysis DOI
Sébastien G. Guillet, Aleksei A. Logvinov, Vladislav A. Voloshkin

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(9), P. 1403 - 1408

Published: Feb. 27, 2023

The area of energy transfer photocatalysis to generate four-membered rings is experiencing an unprecedented level activity. Here, we report operationally simple method toward azetidines from 2-isoxasoline-3-carboxylates and alkenes, using [Au(cbz)(NHC)] complexes as photocatalysts. procedure enables the reaction for a wide range substrates. Mechanistic studies confirm pathway. This contribution adds earlier reported use these gold catalysts potentially versatile tool in chemistry catalysis.

Language: Английский

Citations

9
Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters DOI Creative Commons

Lewis McGhie,

Hannah M. Kortman,

Jenna Rumpf

et al.

Beilstein Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 21, P. 854 - 863

Published: April 30, 2025

The photoactivation of organic molecules via energy transfer (EnT) catalysis is often limited to conjugated systems that have low-energy triplet excited states, with simple alkenes remaining an intractable challenge. ability address this limitation, using high sensitizers, would represent attractive platform for future reaction design. Here, we disclose the alkenylboronic esters established alkene scrambling as a rapid probe identify suitable catalyst and boron motif. Cyclic voltammetry, UV–vis analysis, control reactions support sensitization, enabling intramolecular [2 + 2] cycloaddition be realized accessing 3D bicyclic fragments containing handle.

Language: Английский

Citations

0
Synthesis of Polysubstituted Cyclobutanes through Photoredox Strain-Release/[3,3]-Rearrangement Cascade DOI Creative Commons
Fangqing Zhang, Chun Xu,

Zichun Zhang

et al.

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A photoredox nucleophilic radical strain-release/[3,3]-rearrangement cascade has been established for the synthesis of polysubstituted cyclobutanes by using bicyclo[1.1.0]butanes/cyclobutenes as acceptors and α-silylamines donors.

Language: Английский

Citations

0
[2 + 2] Photocycloadditions of Conformationally Constrained Styrenes Enabled by Triplet Lifetime Extension DOI

Christina Cong,

Nicholas J. Fastuca, Alberto Castanedo

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: June 3, 2025

We report an intermolecular, cross-selective [2 + 2] cycloaddition between cyclic styrenes and olefin acceptors proceeding via visible-light irradiation, enabled by the extended triplet lifetime of styrenes. A broad range olefins, including electron-deficient simple alkenes, (hetero)styrenes, arylimines, vinyl boronate esters, among others, underwent efficient with constrained four-, five-, rigidified six-membered rings, providing rapid access to sp3-rich fused cyclobutane scaffolds. Notably, two electronically similar styrenes, which typically gives statistical mixtures homo- heterodimers, proceeded excellent chemoselectivity yield acyclic without requiring a large excess one reactant, facilitated significant difference in reacting partners. Mechanistic studies DFT calculations support Dexter energy transfer mechanism substrate activation underscore critical role extension enabling observed reactivity. The utility this method is demonstrated total synthesis lindleyanin, only steps.

Language: Английский

Citations

0
Synthesis of 3-borylated cyclobutanols from epihalohydrins or epoxy alcohol derivatives DOI Creative Commons
Tyler McDonald, Sophie A. L. Rousseaux

Chemical Science, Journal Year: 2022, Volume and Issue: 14(4), P. 963 - 969

Published: Dec. 21, 2022

There is an increasing interest in cyclobutanes within the medicinal chemistry community. Therefore, methods to prepare that contain synthetic handles for further elaboration are of interest. Herein, we report a new approach synthesis 3-borylated cyclobutanols via formal [3 + 1]-cycloaddition using readily accessible 1,1-diborylalkanes and epihalohydrins or epoxy alcohol derivatives. 1-Substituted epibromohydrin starting materials provide access borylated containing substituents at three four positions on cyclobutane core, enantioenriched epibromohydrins lead with high levels enantiospecificity (>98%). Finally, derivatization studies demonstrate utility both OH Bpin handles.

Language: Английский

Citations

13