The Rh(II) -catalyzed oxyamination and diamination of alkenes generate 1,2-amino alcohols and 1,2-diamines, respectively, in good to excellent yields and with complete regiocontrol. In the case of diamination, the intramolecular reaction provides an efficient method for the preparation of pyrrolidines, and the intermolecular reaction produces vicinal amines with orthogonal protecting groups. These alkene difunctionalizations proceed by aziridination followed by nucleophilic ring opening induced by an Rh-bound nitrene generated in situ, details of which were uncovered by both experimental and theoretical studies. In particular, DFT calculations show that the nitrogen atom of the putative [Rh]2 =NR metallanitrene intermediate is electrophilic and support an aziridine activation pathway by N⋅⋅⋅N=[Rh]2 bond formation, in addition to the N⋅⋅⋅[Rh]2 =NR coordination mode.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.201600393 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Amide-Directed Highly Enantioselective Hydrogenation of Diverse Acyclic Multisubstituted Alkenes Under Mild Conditions.
Angew Chem Int Ed Engl
January 2025
Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Enantioselective hydrogenation of tetrasubstituted alkenes to form 1,2-contiguous stereocenters is a particularly appealing but highly challenging transformation in asymmetric catalysis. Despite the notable progress achieved in enantioselective hydrogenation over the past decades, enantioselective hydrogenation of all-carbon tetrasubstituted alkenes containing multiple alkyl groups remains an unsolved challenge. Here, we report a rhodium-catalyzed highly diastereo- and enantioselective hydrogenation of diverse acyclic multisubstituted alkenes under mild conditions.
View Article and Find Full Text PDFRhodium-Catalyzed Synthesis of Trifluoromethyl-Containing Allylic Alcohols Via -Alkenyl Transfer with High Stereochemistry Retention.
Org Lett
December 2024
School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Herein, we report the rhodium-catalyzed -alkenyl transfer from tertiary allylic alcohols to aryl trifluoromethyl ketones, which provided an efficient way of preparation of trifluoromethyl-containing -allylic alcohols via β--alkenyl elimination. The key -alkenyl-rhodium species were generated with a high degree of stereochemical retention. This reaction featured a broad substrate scope and good functional tolerance and would offer a fascinating approach for the synthesis of -alkenes.
View Article and Find Full Text PDFRhodium-Catalyzed Enantioselective Ring-Openings of Oxabicyclic Alkenes with Azole Nucleophiles.
J Org Chem
November 2024
Department of Chemistry, University of Toronto, 80 St. George St., Toronto, ON M5S 3H6, Canada.
We report enantioselective ring-openings of oxabicyclic alkenes with azole nucleophiles, generating heterocycle-bearing dihydronaphthalene products. Pyrazoles, triazoles, tetrazoles, and benzo-fused derivatives participate in the ring-opening, with the level of regioselectivity depending on the type and substitution pattern of the heterocyclic partner. Electron-withdrawing azole substituents have a beneficial effect, suppressing the unproductive complexation of a nitrogen with the Rh(I)-bis(phosphine) catalyst.
View Article and Find Full Text PDFA Resorcin[4]arene-Based Phosphite-Phosphine Ligand for the Branched-Selective Hydroformylation of Alkyl Alkenes.
ACS Catal
August 2024
Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
Synthesis of a chelating phosphite-phosphine ligand from a tris(quinoxaline) extended resorcin[4]arene and its application in the rhodium-catalyzed hydroformylation of terminal alkyl alkenes are reported. Rhodium complexes are formed within the cavity of the macrocycle and branched-selective hydroformylation of 1-octene with a / ratio of 5.9 has been achieved at 60 °C under 1:1 H/CO (20 bar).
View Article and Find Full Text PDFRhodium-Catalyzed Highly Enantioselective Hydroboration of Acyclic Tetrasubstituted Alkenes Directed by an Amide.
J Am Chem Soc
June 2024
Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing 100084, China.
Although progress has been made in enantioselective hydroboration of di- and trisubstituted alkenes over the past decades, enantioselective hydroboration of tetrasubstituted alkenes with high diastereo- and enantioselectivities continues as an unmet challenge since the 1950s due to its extremely low reactivity and the difficulties to simultaneously control the regio- and stereoselectivity of a tetrasubstituted alkene. Here, we report highly regio-, diastereo-, and enantioselective catalytic hydroboration of diverse acyclic tetrasubstituted alkenes. The delicate interplay of an electron-rich rhodium complex and coordination-assistance forms a highly adaptive catalyst that effectively overcomes the low reactivity and controls the stereoselectivity.
View Article and Find Full Text PDFWant 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!