Regiodivergent alkyne hydroalkylation to generate different isomers of an alkene from the same alkyne starting material would be beneficial; however, it remains a challenge. Herein, we report a ligand-controlled cobalt-catalyzed regiodivergent alkyne hydroalkylation. The sensible selection of bisoxazoline () and pyridine-oxazoline () ligands led to reliable and predictable protocols that provided ()-1,2-disubstituted and 1,1-disubstituted alkenes with high / stereoselectivity and regioisomeric ratio starting from identical terminal alkyne and alkyl halide substrates and produced trisubstituted alkenes in the case of internal alkynes. This method exhibits a broad scope for terminal and internal alkynes with a wide range of activated and unactivated alkyl halides and shows excellent functional group compatibility.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jacs.2c06279 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Identifying reactive normal modes and their effect on regioselectivity in Myers-Saito and Schmittel cyclization of enyne-allenes: a combined perspective between the reaction force constant and statistical tools.
Phys Chem Chem Phys
January 2025
Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Chile.
This paper presents a theoretical study on the distinguishable regiodivergent C-C Myers-Saito and C-C Schmittel routes of benzannelated enyne-allene cycloaromatizations, in which substitutions on the terminal alkyne by alkyl (-CH, -CHCH, -CH(CH) and -C(CH)) and aryl (-CH and -CH(CH)) groups were included. Mechanistic differences were found between substituents attached to alkynes with and without α-H, whereas in the former the Schmittel cyclization proceeds together with 1,8-H migration, in the latter it does so as the sole primitive event. It was also observed that bulky substituents preferentially favor the C-C Schmittel route, and the statistical prediction of regioselectivity is greatly affected when the ratio of accessible vibrational microstates of the transition states is included, especially in highly competing routes, , ΔΔ → 0.
View Article and Find Full Text PDFLigand-controlled regiodivergent arylation of aryl(alkyl)alkynes and asymmetric synthesis of axially chiral 9-alkylidene-9,10-dihydroanthracenes.
Nat Commun
October 2024
Inner Mongolia Key Laboratory of Fine Organic Synthesis, Inner Mongolia University, 235 West University Street, Hohhot, 010021, China.
Article Synopsis
- The study demonstrates that the addition of arylboronic acids to aryl(alkyl)alkynes can preferentially form 1,1-diarylalkenes (α-addition) when using a rhodium catalyst with a chiral diene ligand.
- The typical reaction produces carbon-carbon bonds at the alkyl-substituted carbon (β-addition) with a different rhodium/DM-BINAP catalyst, highlighting how ligand choice affects regioselectivity.
- Furthermore, this unique α-addition strategy allows for the efficient synthesis of complex molecules like axially chiral alkylidene dihydroanthracenes with high enantioselectivity via a multi-step process involving migration and cyclization.
An unprecedented and highly reactive Pd/C catalytic system has been introduced for the regiodivergent hydrocarboxylation of terminal alkynes to selectively afford various acrylic and cinnamic acids employing oxalic acid as a CO source as well as a promoter for the formation of the active Pd-H complex. Herein, the formation of cinnamic acid is proposed to follow a unique anti-Markovnikov hydroiodination mechanism and the formation of acrylic acid might follow the traditional hydrocarboxylation pathway. Additionally, internal alkynes undergo hydrocarboxylation and carbonylative esterification with aliphatic alcohols to yield different α,β-unsaturated acids and esters respectively.
View Article and Find Full Text PDFLigand-Controlled Regiodivergent Ring Expansion of Benzosilacyclobutenes with Alkynes Route to Axially Chiral Silacyclohexenyl Arenes.
J Am Chem Soc
October 2024
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
A ligand-controlled regiodivergent and enantioselective ring expansion of benzosilacyclobutenes with internal naphthyl alkynes has been achieved by adjusting the ligand cavity size. The ligand ()-8-binaphthyl phosphoramidite, featuring small methyl groups on its arms, provides a spacious cavity that favors sterically demanding Si-Csp ring expansion, predominantly yielding axially chiral ()-1-silacyclohexenyl arenes. In contrast, the ligand ()-spiro phosphoramidite, with bulky -Bu groups on its arms, offers a compact cavity that facilitates less sterically demanding Si-Csp ring expansion, leading primarily to axially chiral ()-2-silacyclohexenyl arenes.
View Article and Find Full Text PDFNickel-catalyzed regiodivergent syn-hydrosilylation of disubstituted alkynes.
Sci Bull (Beijing)
November 2024
Key Laboratory of Organic Synthesis of Jiangsu Province, Suzhou Key Laboratory of Pathogen Bioscience and Anti-infective Medicine, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China. Electronic address:
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!