Syntheses and structures of chiral rhenium-containing phosphonium salts and phosphines with ReCH2P̈Ar2 or ReCH(R)P̈Ar2 linkages; enantioselective catalysis of intramolecular Morita-Baylis-Hillman and Rauhut-Currier reactions

Seidel F, O'Brien MJ, Hampel F, Gladysz JA (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Dalton Transactions Royal Society of Chemistry

DOI: 10.1039/d5dt01102g

Abstract

Easily accessed (η5-C5H5)Re(NO)(PPh3)(CH3) (2) is treated with Ph3C+ PF6− (−78 °C) to generate the methylidene cation [(η5-C5H5)Re(NO)(PPh3)(Formula presented) CH2)]+ and then secondary phosphines PAr2H (Ar = a, Ph; b, p-tol; c, p-C6H4OCH3; d, p-C6H4N(CH3)2; e, 2-biphen; f, α-naph) to give the phosphonium salts [(η5-C5H5)Re(NO)(PPh3)(CH2PAr2H)]+ PF6− ([1a-f-H]+ PF6−, 87-94%). Additions of t-BuOK yield the phosphines 1a-f (64-91%). Analogous procedures starting with (S)-2 give enantiopure (S)-1a-d in comparable yields. The ethyl complex (S)-(η5-C5H5)Re(NO)(PPh3)(CH2CH3) is similarly treated with Ph3C+ PF6− to generate the ethylidene cation (S)-(sc)-[(η5-C5H5)Re(NO)(PPh3)( CHCH3)]+ and then PPh2H to give enantiopure and diastereopure (SReSC)-[(η5-C5H5)Re(NO)(PPh3)(CH(CH3)PPh2H)]+ PF6− (51%). Addition of t-BuOK yields the corresponding ReCH(CH3)PPh2 adduct. The crystal structures of [1c,d-1 PF6−] are determined and analyzed. Most of the ReCH2PAr2 species catalyze intramolecular Morita-Baylis-Hillman reactions of R(CO)CH CH(CH2)nCH2CHO (n/R = 1/Ph, 1/S-i-Pr, 2/p-tol 2/Me) in C6H6 or C6H5Cl (20 °C) to give R(CO) (Formula presented). HOH (99-86%, 74-38% ee with (S)-1a) or Rauhut-Currier reactions of R(CO)CH CHCH2CH2CH CH(CO)R (R = Ph, S-i-Pr) to give R(CO)C C HCH2CH2C HCH2(CO)R (87-82%, 56-42% ee with (S)-1a).

Authors with CRIS profile

Falk Seidel Lehrstuhl für Anorganische und Allgemeine Chemie Frank Hampel Lehrstuhl für Organische Chemie I

Involved external institutions

Texas A&M University US United States (USA) (US)

How to cite

APA:

Seidel, F., O'Brien, M.J., Hampel, F., & Gladysz, J.A. (2025). Syntheses and structures of chiral rhenium-containing phosphonium salts and phosphines with ReCH2P̈Ar2 or ReCH(R)P̈Ar2 linkages; enantioselective catalysis of intramolecular Morita-Baylis-Hillman and Rauhut-Currier reactions. Dalton Transactions. https://doi.org/10.1039/d5dt01102g

MLA:

Seidel, Falk, et al. "Syntheses and structures of chiral rhenium-containing phosphonium salts and phosphines with ReCH2P̈Ar2 or ReCH(R)P̈Ar2 linkages; enantioselective catalysis of intramolecular Morita-Baylis-Hillman and Rauhut-Currier reactions." Dalton Transactions (2025).

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