13632-79-6Relevant academic research and scientific papers
Hydroxyl Assisted, Photoredox/Cobalt Co-catalyzed Semi-Hydrogenation and Tandem Cyclization of o-Alkynylphenols for Access to 2,3-Dihydrobenzofurans
Tian, Wan-Fa,Zhu, Yao,He, Yong-Qin,Wang, Mei,Song, Xian-Rong,Bai, Jiang,Xiao, Qiang
supporting information, p. 730 - 736 (2020/12/15)
Herein, a hydroxyl assisted, photoredox/cobalt co-catalyzed semi-hydrogenation and tandem cyclization of o-alkynylphenols is developed towards direct assembly of 2,3-dihydrobenzofurans. Moderate to good yields were obtained for a range of sterically and electronically diverse 2-propynolphenols under mild conditions. Mechanistic studies demonstrated the inevitable role of the alcoholic hydroxyl group with (Z)-alkene as the real intermediate. Finally, a key low-valent cobalt catalyzed intramolecular hydroetherification of alkene is proposed. (Figure presented.).
Synthesis, Characterization, and Reactivity of Cationic Gold Diarylallenylidene Complexes
Kim, Nana,Widenhoefer, Ross A.
, p. 4722 - 4726 (2018/03/27)
Methoxide abstraction from gold acetylide complexes of the form (L)Au[η1-C≡CC(OMe)ArAr′] (L=IPr, P(tBu)2(ortho-biphenyl); Ar/Ar′=C6H4X where X=H, Cl, Me, OMe) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) at ?78 °C resulted in the formation of the corresponding cationic gold diarylallenylidene complexes [(L)Au=C=C=CArAr′]+ OTf? in ≥85±5 % yield according to 1H NMR analysis. 13C NMR and IR spectroscopic analysis of these complexes established the arene-dependent delocalization of positive charge on both the C1 and C3 allenylidene carbon atoms. The diphenylallenylidene complex [(IPr)Au=C=C=CPh2]+ OTf? reacted with heteroatom nucleophiles at the allenylidene C1 and/or C3 carbon atom.
HBF4-Catalysed Nucleophilic Substitutions of Propargylic Alcohols
Barreiro, Elena,Sanz-Vidal, Alvaro,Tan, Eric,Lau, Shing-Hing,Sheppard, Tom D.,Dez-Gonzlez, Silvia
supporting information, p. 7544 - 7549 (2016/01/26)
The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C-O, C-N and C-C bonds in technical acetone and in air. Good to excellent yields and good chemoselectivities were obtained using low acid loading (typically 1 mol-%) under simple reaction conditions. The activity of HBF4 (aq. solution) as a catalyst in propargylation reactions is presented. C-O, C-N and C-C bonds were formed in technical acetone and in air. Good to excellent yields were obtained using low acid loading (typically 1 mol-%) under mild reaction conditions.
Ferrocenium hexafluorophosphate as an inexpensive, mild catalyst for the etherification of propargylic alcohols
Queensen, Matthew J.,Rabus, Jordan M.,Bauer, Eike B.
, p. 221 - 229 (2015/08/06)
Commercial ferrocenium hexafluorophosphate ([FeCp2]PF6) was found to be an efficient catalyst for the etherification of terminal, tertiary propargylic alcohols with primary and secondary alcohols (5 h to 3 days reaction time at 40 °C in CH2Cl2, 3 mol% catalyst loading). The propargylic ether products were isolated in 90-20% yields. The alcohols and propargylic alcohols were employed in an equimolar amount and no further additives were required. For a purely aromatic propargylic alcohol, the isolated yields were lower than those for a mixed aromatic-aliphatic propargylic alcohol. Through monitoring reactant consumption and product formation over time, we found that the aromatic propargylic alcohol undergoes yield-diminishing Meyer-Schuster rearrangements to the aldehyde more easily than the mixed aromatic-aliphatic propargylic alcohol. The employment of [Fe(Cp)2]PF6 as a single electron oxidant has the potential to add a new direction in the development of catalysts for the title reaction based on single electron transfer processes.
The coordination chemistry and reactivity of amino-dithiaphospholanes with rhodium, iridium, and ruthenium
Costin, Stephen,Sedinkin, Sergey L.,Bauer, Eike B.
scheme or table, p. 922 - 925 (2009/05/27)
Novel amino-dithiaphospholane complexes of ruthenium, iridium, and rhodium were synthesized, and their properties were studied. Reaction of the new amino-dithiaphospholane (RS)2PNR2′ (R = binaphthyl, R′ = CH2Ph,
Rhodium-catalyzed hydroalkynylation of internal alkynes with silylacetylenes: An alkynylrhodium(I) intermediate generated from the hydroxorhodium(I) complex [Rh(OH)(binap)]2
Nishimura, Takahiro,Guo, Xun-Xiang,Ohnishi, Kohei,Hayashi, Tamio
, p. 2669 - 2672 (2008/09/19)
A highly selective hydroalkynylation of internal alkynes with silylacetylenes giving 1,3-enynes was realized by use of a hydroxorhodium catalyst. As a key intermediate in the catalytic cycle, an alkynylrhodium(I) complex was isolated and investigated for its structure and reactivity.
A facile access to spiro furanone skeleton based on Pd(II)-mediated cyclization-carbonylation of propargylic esters
Kato, Keisuke,Nouchi, Hideaki,Ishikura, Keisuke,Takaishi, Satoshi,Motodate, Satoshi,Tanaka, Hikaru,Okudaira, Kazuho,Mochida, Tomoyuki,Nishigaki, Ryuichiro,Shigenobu, Koki,Akita, Hiroyuki
, p. 2545 - 2554 (2007/10/03)
The oxidative cyclization-carbonylation of propargylic esters mediated by Pd(II) afforded cyclic orthoesters, which were hydrolyzed into γ-acetoxy-β-ketoesters. Based on the NMR experiments, it was presumed that the cyclization reaction was initiated by a
Unusual formation of cyclic-orthoesters by Pd(II)-mediated cyclization-carbonylation of propargylic acetates
Kato, Keisuke,Yamamoto, Yasuhiro,Akita, Hiroyuki
, p. 6587 - 6590 (2007/10/03)
The oxidative cyclization-methoxycarbonylation of propargylic acetates 1 in the presence of (CH3CN)2PdCl2/p-benzoquinone in methanol under carbon monoxide atmosphere (balloon) afforded (E)-cyclic-orthoesters 5 in moderate
2-Propynylamines from 1,1-Dibromo-1-alkenes
Frey, Herbert,Kaupp, Gerd
, p. 931 - 934 (2007/10/02)
Easily accessible 1,1-dibromo-1-alkenes react with primary or secondary amines in a complex series of reactions to give directly N-substituted or N,N-disubstituted (1-Alkyl-1-aryl-2-propynyl)amines 5 in useful yields.This simple method avoids the isolation of intermediates (bromoacetylenes or bromoallenes) and makes a series of 2-propynylamines with an acetylenic hydrogen available.
