Enantioselective cyanosilylation of aldehydes catalyzed by novel camphor derived Schiff bases-titanium(IV) complexes
作者:Ewelina Błocka、Mariusz J. Bosiak、Mirosław Wełniak、Agnieszka Ludwiczak、Andrzej Wojtczak
DOI:10.1016/j.tetasy.2014.03.001
日期:2014.4
Five tridentate Schiff bases have been prepared from (1R,2S,3R,4S)-3-amino-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol and salicylaldehydes. X-ray structure investigation revealed differences in their molecular conformation, and their titanium(IV) complexes have been studied with NMR techniques. Among them the complex with the Schiffbase obtained from 2-hydroxy-3-isopropylbenzaldehyde, is the most selective
yttrium‐pillared silicotungstate dimer (see picture) catalyzes the cyanosilylation of structurally diverse ketones and aldehydes with trimethylsilyl cyanide (TMSCN). The reactions proceed selectively and afford the corresponding cyanohydrin trimethylsilyl ethers. The catalytic performance is significant, in particular for aldehydes, with a turnover number of 18 000 and a turnover frequency of 540 000 h−1
The Addition of Trimethylsilyl Cyanid to Carbonyl Compounds Using Yb(OTf)<sub>3</sub> as Lewis Acid Catalyst
作者:Yang Yang、Dong Wang
DOI:10.1055/s-1997-1071
日期:——
Yb(OTf)3 was found to be an effective catalyst in the addition of TMSCN to various carbonyl compounds. Highly chemoselective process was observed in the reactions of α-keto aldehyde acetals. Catalyst Yb(OTf)3 is tolerant to the hydroxy group of glyoxylate hydrates used. Catalytic diastereoselective trimethylsilylcyanation of chiral aldehydes and cyanation of glyoxylate hydrates can be carried out under mild condition with moderate de.
Cyanosilylation of aldehydes and ketones. A convenient route to cyanohydrin derivatives
作者:D. A. Evans、L. K. Truesdale、G. L. Carroll
DOI:10.1039/c39730000055
日期:——
A wide variety of aldehydes and ketones reacts with trimethylsilyl cyanide under both thermal and catalytic conditions to give α-silyloxy nitriles which may be useful intermediates and protective groups in organic synthesis.
Tri-lacunary polyoxometalates of Na8H[PW9O34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
作者:Shen Zhao、Yang Chen、Yu-Fei Song
DOI:10.1016/j.apcata.2014.01.017
日期:2014.4
development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34]·7H2O and Na8H[B-PW9O34]·19H2O (Na-A-PW9 and Na-B-PW9) as highlyselective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 °C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity