We report carbonyl-stabilized phosphorus ylides as general and efficient catalysts for the cyanosilylation of ketones. The ,-diethylacetamide derived phosphorane is identified as an extremely efficient catalyst for the cyanosilylation of dialkyl ketones, alkyl aryl ketones, diaryl ketones, and α,β-unsaturated enones with catalyst loading down to 0.005 mol %, the lowest ever known for ketone cyanosilylation. Aldehydes, aldimines, and ketimines are also viable substrates. By NMR and React IR analysis, as well as electrical conductivity experiments, it is proposed that the phosphorane acts as a Lewis base in order to mediate the reaction via the desilylative nucleophilic activation of TMSCN.
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http://dx.doi.org/10.1021/acs.joc.9b03347 | DOI Listing |
J Org Chem
November 2020
Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development and Shanghai Key Laboratory of Green Chemistry and Chemical Process, East China Normal University, Shanghai 200062, P. R. China.
We report carbonyl-stabilized phosphorus ylides as general and efficient catalysts for the cyanosilylation of ketones. The ,-diethylacetamide derived phosphorane is identified as an extremely efficient catalyst for the cyanosilylation of dialkyl ketones, alkyl aryl ketones, diaryl ketones, and α,β-unsaturated enones with catalyst loading down to 0.005 mol %, the lowest ever known for ketone cyanosilylation.
View Article and Find Full Text PDFInorg Chem
March 2001
Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
A novel method is reported for generation of the difficult-to-obtain (imine)Pt(II) compounds that involves reduction of the corresponding readily available Pt(IV)-based imines by carbonyl-stabilized phosphorus ylides, Ph3P=CHCO2R, in nonaqueous media. The reaction between neutral (imino)Pt(IV) compounds [PtCl4[NH=C(Me)ON=CR1R2]2] [R1R2 = Me2, (CH2)4, (CH2)5, (Me)C(Me)=NOH], [PtCl4[NH=C(Me)ONR2]2] (R = Me, Et, CH2Ph), (R1 = H; R2 = Ph or C6H4Me; R3 = Me) as well as anionic-type platinum(IV) complexes (Ph3PCH2Ph)[PtCl5[NH=C(Me)ON=CR2]] [R2 = Me2, (CH2)4, (CH2)5] and 1 equiv of Ph3P=CHCO2R (R = Me, Et) proceeds under mild conditions (ca. 4 h, room temperature) to give selectively the platinum(II) products (in good to excellent isolated yields) without further reduction of the platinum center.
View Article and Find Full Text PDFInorg Chem
October 1996
University Chemical Laboratory, Lensfield Road, CB2 1EW Cambridge, U.K.
PtCl(2) reacts with C(6)F(5)CN to give trans-[PtCl(2)(NCC(6)F(5))(2)] (1) which, in turn, reacts with carbonyl-stabilized phosphorus ylides Ph(3)P=CHR [R = C(O)Me, CO(2)Et] to give trans-[PtCl(2){NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}{NCC(6)F(5)}] (2a), trans-[PtCl(2){NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}(2)] (3a), trans-[PtCl(2){E-NH=C(C(6)F(5))C(=PPh(3))C(O)Me}(2)] (3b) or trans-[PtCl(2){E-N(=PPh(3))C(C(6)F(5))=CHCO(2)Et}{E-NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}] (4), depending on the reaction conditions. Similarly, Ph(3)P=CHCO(2)Me reacts with trans-[PtCl(2)(NCMe)(2)] to give trans-[PtCl(2){NH=CMeC(=PPh(3))CO(2)Me}(NCMe)] (2b). Complex 3b.
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