61685-29-8Relevant academic research and scientific papers
Platinum-catalyzed one-pot alkenylation of aldehydes using alkynes and triethylsilane: Dual catalysis by platinum(II) chloride
Kinoshita, Hidenori,Uemura, Ryousuke,Fukuda, Daiki,Miura, Katsukiyo
, p. 5538 - 5541 (2013/11/19)
The PtCl2-catalyzed hydrosilylation of terminal alkynes with triethylsilane and subsequent alkenylation of aldehydes with the resultant (E)-alkenylsilanes in a one-pot manner are described. By adding p-benzoquinone and LiI, the latter alkenylation step proceeds smoothly to give allyl silyl ethers in moderate to high yields. This one-pot alkenylation is tolerant to a reasonable range of functional groups. PtCl2 plays a dual role as hydrosilylation and alkenylation catalysts.
Nozaki-Hiyama-Kishi reactions catalytic in chromium
Fürstner, Alois,Shi, Nongyuan
, p. 12349 - 12357 (2007/10/03)
A procedure is described which allows for the first time to perform chromium-catalyzed additions of organic halides to aldehydes ("Nozaki-Hiyama-Kishi reactions"). The reactions are mediated by trimethylchlorosilane, and the active Cr2+ species is constantly recycled by means of nontoxic, commercial manganese powder as the stoichiometric reductant. This method nicely applies to different substituted aryl, heteroaryl, alkynyl, alkenyl, and allyl halides as well as to alkenyl inflates as the starting materials and rivals its stoichiometric precedent in terms of efficiency, practicability, and chemo- and diastereoselectivity. Specifically, it has been demonstrated that the addition of crotyl bromide to various aldehydes is highly stereoconvergent, i.e. the respective anti-configurated homoallyl alcohols are obtained with excellent diastereomeric excess independent of whether the starting halide is (E)- or (Z)-configurated. In accordance with the likely catalytic cycle, both CrCl2(cat.) or CrCl3(cat) turned out to efficiently mediate reactions of this type, with the latter being preferred for practical reasons. Finally, attempts were made to optimize the number of turnovers in chromium. In this context the use of either chromocene (Cp2Cr) or CpCrCl2·THF as "pre-catalysts" were found to significantly upgrade the efficiency of such C-C bond formations, with ≤ 1 mol % of chromium being required in these cases for quantitative conversions.
