299187-79-4Relevant academic research and scientific papers
Enantioselective C-H crotylation of primary alcohols via hydrohydroxyalkylation of butadiene
Zbieg, Jason R.,Yamaguchi, Eiji,McInturff, Emma L.,Krische, Michael J.
scheme or table, p. 324 - 327 (2012/07/28)
The direct, by-product-free conversion of basic feedstocks to products of medicinal and agricultural relevance is a broad goal of chemical research. Butadiene is a product of petroleum cracking and is produced on an enormous scale (about 12 × 106 metric tons annually). Here, with the use of a ruthenium catalyst modified by a chiral phosphate counterion, we report the direct redox-triggered carbon-carbon coupling of alcohols and butadiene to form products of carbonyl crotylation with high levels of anti- diastereoselectivity and enantioselectivity in the absence of stoichiometric by-products.
Enhanced anti-diastereo- and enantioselectivity in alcohol-mediated carbonyl crotylation using an isolable single component iridium catalyst
Gao, Xin,Townsend, Ian A.,Krische, Michael J.
supporting information; experimental part, p. 2350 - 2354 (2011/05/30)
The cyclometalated iridium complex (S)-I derived from [Ir(cod)Cl] 2, 4-cyano-3-nitrobenzoic acid, allyl acetate, and (S)-SEGPHOS is conveniently isolated by precipitation or through conventional silica gel flash chromatography. This single-component precatalyst allows alcohol mediated carbonyl crotylations to be performed at significantly lower temperature, resulting in enhanced levels of anti-diastereo- and enantioselectivity. Most significantly, the chromatographically isolated precatalyst (S)-I enables carbonyl crotylations that are not possible under previously reported conditions involving in situ generation of (S)-I.
Unusual E-selective ring-closing metathesis to form eight-membered rings
Matsui, Ryosuke,Seto, Kentaro,Fujita, Kazuhiro,Suzuki, Takahiro,Nakazaki, Atsuo,Kobayashi, Susumu
supporting information; experimental part, p. 10068 - 10073 (2011/03/16)
Tied back: The title reaction was observed when a silicon-tethered diene was treated with the Hoveyda-Grubbs second-generation catalyst. The structural requirements for the E-olefin-forming ring-closing metathesis, and the transition state leading to E olefin are discussed. This methodology will be useful in the synthesis of polyketides containing a pent-2-ene-1,5-diol unit. Copyright
Anti-diastereo-and enantioselective carbonyl crotylation from the alcohol or aldehyde oxidation level employing a cyclometallated iridium catalyst: α-methyl allyl acetate as a surrogate to preformed crotylmetal reagents
Kim, In Su,Han, Soo Bong,Krische, Michael J.
supporting information; experimental part, p. 2514 - 2520 (2009/08/16)
Under the conditions of transfer hydrogenation employing an ortho-cyclometallated iridium catalyst generated in situ from [Ir(cod)Cl] 2, 4-cyano-3-nitrobenzoic acid and the chiral phosphine ligand (S)-SEGPHOS, α-methyl allyl acetate couples to
