Article

Enantioselective C-H crotylation of primary alcohols via hydrohydroxyalkylation of butadiene.

Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712, USA.
Science (impact factor: 31.2). 03/2012; 336(6079):324-7. DOI:10.1126/science.1219274 pp.324-7
Source: PubMed

ABSTRACT 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 × 10(6) 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.

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  • Article: Iridium Catalyzed Hydro-hydroxyalkylation of Butadiene: Carbonyl Crotylation.
    Jason R Zbieg, Takeo Fukuzumi, Michael J Krische
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    ABSTRACT: Exposure of alcohols 1a-1i to butadiene in the presence of a cyclometallated iridium catalyzed derived from allyl acetate, 4-methoxy-3-nitrobenzoic acid and BIPHEP (2,2'-bis(diphenylphosphino)biphenyl) results in hydrogen transfer to generate aldehyde-allyliridium pairs, which engage in C-C coupling to form products of carbonyl crotylation. Under related conditions using 1,4-butanediol as hydrogen donor, butadiene reductively couples to aldehydes 2e-2g and 2i to furnish carbonyl crotylation products 3e-3g and 3i. Thus, butadiene mediated carbonyl crotylation occurs with equal facility from the alcohol or aldehyde oxidation level with complete levels of branched regioselectivity.
    Advanced Synthesis & Catalysis 10/2010; 352(14-15):2416-2420. · 6.05 Impact Factor
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Keywords

agricultural relevance
 
anti-diastereoselectivity
 
broad goal
 
by-product-free conversion
 
carbonyl crotylation
 
chiral phosphate counterion
 
direct redox-triggered carbon-carbon coupling
 
enantioselectivity
 
enormous scale
 
form products
 
products
 
stoichiometric by-products
 

Jason R Zbieg