2396-84-1Relevant articles and documents
Tandem regio- And stereoselective organocuprate-mediated bis-allylic substitutions
Dieter, R. Karl,Guo, Fenghai
, p. 2087 - 2090 (2008)
anti-5-Acetoxy-4-halo-α,β-enoates undergo sequential or tandem reactions with two different magnesium cuprate reagents to afford anti-2,3-dialkyl-4,5-enoates in high chemical yield and with excellent diastereoselectivity. The one-pot tandem procedure can be achieved with 30 mol % of CuCN and affords a rapid stereoselective combinatorial approach to vicinal disubstituted γ,λ-enoates containing functionality a either end of the carbon chain for subsequent functional group elaboration. The methodology should provide a powerful practical strategy for acyclic stereoselection.
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Rigg,Rosenthal
, p. 2865,2867 (1949)
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Z-Selective phosphine promoted 1,4-reduction of ynoates and propynoic amides in the presence of water
Drikermann, Denis,Kupfer, Stephan,Seifert, Fabian,Steinmetzer, Johannes,Vilotijevic, Ivan,Zi, You
supporting information, p. 6092 - 6097 (2021/07/21)
Phosphine-mediated reductions of substituted propynoic esters and amides in the presence of water yield the partially reduced α,β-unsaturated esters and amides with highZ-selectivity. The competitivein situ ZtoE-isomerization of the product in some cases lowers theZtoEratios of the isolated α,β-unsaturated carbonyl products. Reaction time and the amounts of phosphine and water in the reaction mixture are the key experimental factors which control the selectivity by preventing or reducing the rates ofZ- toE-product isomerization. Close reaction monitoring enables isolation of theZ-alkenes with high selectivities. The computational results suggest that the reactions could be highlyZ-selective owing to the stereoselective formation of theE-P-hydroxyphosphorane intermediate.
OMS-2 for aerobic, catalytic, one-pot alcohol oxidation-wittig reactions: Efficient access to α,β-unsaturated esters
Kona, Jagadeswara R.,King'Ondu, Cecil K.,Howell, Amy R.,Suib, Steven L.
, p. 749 - 752 (2014/03/21)
Manganese oxide octahedral molecular sieve (OMS) materials with well-defined pores have been extensively studied over two decades due to their intriguing chemical and physical properties. OMS-2, the synthetic cryptomelane form of manganese oxide, was synthesized by a modified reflux method and was found to be highly active for obtaining α,β-unsaturated esters (up to 95 % yield and with high diastereoselectivities) from a variety of benzyl, heteroaryl, allyl and alkyl alcohols via one-pot alcohol oxidation-Wittig reaction. The transformation utilizes air as the stoichiometric oxidant, and the inexpensive catalyst can be recovered and reused. Filter and use again! Porous manganese oxide molecular sieve based catalysts were found to efficiently promote the oxidation of a variety of alcohols to the aldehydes, which reacted insitu with stabilized Wittig reagent, providing almost exclusively E-α,β-unsaturated esters in good to excellent yields. The heterogeneous catalyst used was made from inexpensive starting materials, and the recovered catalyst was found to be reusable with a modest loss in activity.
Synthesis, antimicrobial evaluation and QSAR studies of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides
Kumar, Davinder,Kapoor, Archana,Thangadurai, Ananda,Kumar, Pradeep,Narasimhan, Balasubramanian
experimental part, p. 1293 - 1296 (2012/01/07)
A series of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides (1-20) was synthesized and tested for in vitro antimicrobial activity. The results of antimicrobial studies indicated that the compounds having dinitro, methoxy, hydroxy and nitro substituents on phenyl ring of the aromatic acids were most active ones. The QSAR investigation indicated the importance of the topological parameter, third order molecular connectivity index ( 3χ) in describing the antimicrobial activity of synthesized hydrazides.
