Stereoinvertive SN1 Through Neighboring Group Participation DOI Creative Commons
Rahul Suresh, Noam Orbach, Ilan Marek

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(31)

Published: May 20, 2024

Abstract Neighboring group participation, the assistance of non‐conjugated electrons to a reaction center, is fundamental phenomenon in chemistry. In framework nucleophilic substitution reactions, neighboring participation known cause rate acceleration, first order kinetics (S N 1), and retention configuration. The latter result double inversion: one when displaces leaving group, second nucleophile substitutes group. This powerful control stereoretention has been widely used organic synthesis for more than century. However, may also lead inversion configuration, which often overlooked. Herein, we review this unique mode stereoinversion, dividing relevant reactions into three classes with aim introduce fresh perspective on different modes stereoinversion via as well factors that stereochemical outcome.

Language: Английский

Taming nonclassical carbocations to control small ring reactivity DOI Creative Commons
Ryan E. McNamee, Nils Frank, Kirsten E. Christensen

et al.

Science Advances, Journal Year: 2024, Volume and Issue: 10(2)

Published: Jan. 12, 2024

Prediction of the outcome ring opening small organic rings under cationic conditions can be challenging due to intermediacy nonclassical carbocations. For example, solvolysis cyclobutyl or cyclopropylmethyl derivatives generates up four products on nucleophilic capture elimination via cyclopropylcarbinyl and bicyclobutonium ions. Here, we show that such reaction outcomes controlled by subtle changes structure carbocation. Using bicyclo[1.1.0]butanes as cation precursors, regio- stereochemistry is shown depend degree nature substituents intermediates. Reaction are rationalized using computational models, resulting in a flowchart predict product formation from given precursor.

Language: Английский

Citations

12

Rh-catalyzed double carbonylation of cyclopropenes toward valerolactone derivatives via cleavage of carbon–carbon double bonds DOI

Song‐Zhou Cai,

Can Li,

Suliang Wang

et al.

Science China Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

Language: Английский

Citations

1

Stereospecific molecular rearrangement via nucleophilic substitution at quaternary stereocentres in acyclic systems DOI

Kaushalendra Patel,

Ilan Marek

Nature Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

Language: Английский

Citations

1

Stereoselective Construction of Tertiary Homoallyl Alcohols and Ethers by Nucleophilic Substitution at Quaternary Carbon Stereocenters DOI Creative Commons
Chen Xu,

Kaushalendra Patel,

Ilan Marek

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(3)

Published: Nov. 22, 2022

An efficient method for the stereoselective construction of tertiary C-O bonds via a stereoinvertive nucleophilic substitution at quaternary carbon stereocenter cyclopropyl carbinol derivatives using water, alcohols and phenols as nucleophiles has been developed. This reaction proceeds under mild conditions tolerates several functional groups, providing new access to formation highly congested homoallyl ethers.

Language: Английский

Citations

21

Cyclopropylcarbinyl cation chemistry in synthetic method development and natural product synthesis: cyclopropane formation and skeletal rearrangement DOI
Jiaxin Xie, Guangbin Dong

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(9), P. 2346 - 2358

Published: Jan. 1, 2023

In this Review, the underrecognized utilities of cyclopropylcarbinyl cation chemistry are summarized in cyclopropane synthesis and skeletal rearrangements, their applications natural product total highlighted.

Language: Английский

Citations

13

Oxidative cross-coupling of quinoxalinones with indoles enabled by acidochromism DOI
Jie Huang, Long Wang, Xiang‐Ying Tang

et al.

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(13), P. 2709 - 2714

Published: Jan. 1, 2023

We report a new gate for changing photo inactive compounds into photocatalysts with easy operation, good tolerance of functional groups, and considerable yield. demonstrate the synthesis natural products Azacephalandole A Cephalandole in high yields.

Language: Английский

Citations

11

Cyclopropylcarbinyl-to-Homoallyl Carbocation Equilibria Influence the Stereospecificity in the Nucleophilic Substitution of Cyclopropylcarbinols DOI
Sean P. Larmore, Pier Alexandre Champagne

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 6947 - 6954

Published: May 4, 2023

The synthesis of quaternary homoallylic halides and trichloroacetates from cyclopropylcarbinols, as reported by Marek (J. Am. Chem. Soc.2020, 142, 5543-5548), is one the few examples stereospecific nucleophilic substitution involving chiral bridged carbocations. However, for phenyl-substituted substrates, poor specificity observed mixtures diastereomers are obtained. To understand nature intermediates involved explain loss certain we have performed a computational investigation reaction mechanism using ωB97X-D optimizations DLPNO-CCSD(T) energy refinements. Our results indicate that cyclopropylcarbinyl cations stable in this reaction, while bicyclobutonium structures high-energy transition not involved. Instead, multiple rearrangement pathways were located, including ring openings to cations. activation barriers required reach such correlated substituents; direct attack on kinetically favored most systems, rearrangements become competitive with leading through rearranged carbocation intermediates. As such, reactions depend energies access their corresponding structures, which selectivity guaranteed.

Language: Английский

Citations

11

Substituent Effects on the Equilibria between Cyclopropylcarbinyl, Bicyclobutonium, Homoallyl, and Cyclobutyl Cations DOI
Sean P. Larmore, Pier Alexandre Champagne

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(11), P. 8146 - 8156

Published: May 16, 2024

The cyclopropylcarbinyl (CPC) and bicyclobutonium (BCB) structures of the C

Language: Английский

Citations

4

Organophosphorus-Catalyzed Borylative Ring-Opening of Vinylcyclopropanes: A Stereoselective Route to δ-Valerolactones DOI
Krishna Biswas,

Aankhi Khamrai,

Subrata Malik

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(11), P. 1805 - 1810

Published: March 15, 2023

We report an operationally simple route to δ-valerolactones through organophosphorus-catalyzed borylative ring-opening/allylation of vinylcyclopropanes providing δ-hydroxy esters stereoselectively. The were lactonized obtain densely substituted δ-valerolactones. present methodology exhibited enhanced functional group tolerance compared the existing metal-mediated methods. A plausible mechanism for ring-opening reaction has been suggested. 31P NMR studies indicated involvement a phosphonium zwitterionic species. synthetic utility intermediate allyl boronates was demonstrated.

Language: Английский

Citations

9

Highly Diastereoselective Preparation of Tertiary Alkyl Isonitriles by Stereoinvertive Nucleophilic Substitution at a Nonclassical Carbocation DOI Creative Commons
Chen Xu, Ilan Marek

Organic Letters, Journal Year: 2023, Volume and Issue: 25(13), P. 2285 - 2288

Published: March 28, 2023

A highly efficient SnCl4-catalyzed nucleophilic isocyanation of cyclopropyl ethers has been developed. The reaction proceeds at the quaternary carbon stereocenter cyclopropane with a complete inversion configuration, providing new avenue for construction synthetically challenging tertiary alkyl isonitriles high diastereopurity. diversity incorporated isocyanide group demonstrated by transformation into corresponding amines, amides, and cyclic ketoimines.

Language: Английский

Citations

9