164853-29-6Relevant academic research and scientific papers
An easy conversion of the Baylis-Hillman adducts into tert- butyldimethylsilyl ethers with tert-butyldimethylsilyl chloride and Li 2S
Mamaghani, Manouchehr,Badrian, Abed
, p. 2429 - 2435 (2004)
The hydroxy group of the Baylis-Hillman adducts is protected with the t-butyldimethylsilyl (TBDMS) group using the reaction of adducts 1a-h with tert-butyldimethylsilyl chloride (TBDMSCl) in the presence of lithium sulfide under nearly acidic reaction con
A versatile approach to noncoded β-hydroxy-α-amino esters and α-amino acids/esters from morita-baylis-hillman adducts
Ullah, Hamid,Ferreira, Andr V.,Bendassolli, Jos A.,Rodrigues, Manoel T.,Formiga, Andr Luiz B.,Coelho, Fernando
, p. 113 - 123 (2015/02/02)
A simple and straightforward approach to the diastereoselective synthesis of noncoded β-hydroxy-α-amino esters from Morita-Baylis-Hillman (MBH) adducts is described. The strategy is based on a one-pot sequence involving an oxidative cleavage of the double bond of silylated Morita-Baylis-Hillman adducts, followed by the reaction with hydroxylamine hydrochloride/pyridine to form oximes. The stereoselective reduction of the oximes with the mixture MoCl5·nH2O/NaBH3CN led to the corresponding anti-β-hydroxy-α-amino esters in four steps in good overall yield and with diastereoselectivity higher than 95%. A slight modification of the synthetic approach has allowed for the racemic synthesis of a set of noncoded α-amino esters/acids and DOPA
Hyphenating the curtius rearrangement with morita-baylis-hillman adducts: Synthesis of biologically active acyloins and vicinal aminoalcohols
Amarante, Giovanni W.,Cavallaro, Mayra,Coelho, Fernando
experimental part, p. 1568 - 1584 (2011/11/06)
Using Morita-Baylis-Hillman adducts as substrates, the Curtius rearrangement was performed in a sequence that allowed the synthesis of several hydroxy-ketones (acyloins) with great structural diversity and in good overall yields. These acyloins in turn were easily transformed into 1,2-anti aminoalcohols through a highly diastereoselective reductive amination step. The synthetic utility of these approaches was exemplified by performing the syntheses of (±)-bupropion, a drug used to treat the abstinence syndrome of smoker and (±)-spisulosine, a potent anti-tumoral compound originally isolated form a marine source.
Ozonolysis of Morita-Baylis-Hillman adducts originated from aromatic aldehydes: an expeditious diastereoselective approach for the preparation of α,β-dihydroxy-esters
Abella, Carlos A.M.,Rezende, Patrícia,Lino de Souza, Michele F.,Coelho, Fernando
, p. 145 - 148 (2008/04/13)
We disclose herein ozonolysis of Morita-Baylis-Hillman adducts originated from aromatic aldehydes. This efficient reaction provides α-ketoesters with different substitution patterns on the aromatic ring. Diastereoselective reduction of the corresponding α-ketoester obtained in the oxidative cleavage step provides α,β-dihydroxy-esters with excellent degree of anti diastereoselection. The method is simple and easy to execute and is therefore a valuable alternative to prepare either α-ketoesters or α,β-dihydroxy-esters.
Acyloins from Morita-Baylis-Hillman adducts: an alternative approach to the racemic total synthesis of bupropion
Amarante, Giovanni W.,Rezende, Patrícia,Cavallaro, Mayra,Coelho, Fernando
, p. 3744 - 3748 (2008/09/21)
In this Letter, we describe an easy and straightforward strategy for the preparation of acyloins (α-hydroxyketones) from Morita-Baylis-Hillman adducts, based on a Curtius rearrangement. Different acyloins were obtained with good overall yield (>40% for three steps). To exemplify the synthetic usefulness of this strategy, total synthesis of (±)-bupropion, a dopamine, and nor-epinefrine reuptake inhibitor has been accomplished in eight steps with an overall yield of 25%.
Diastereoselective epoxidation of allylic diols derived from Baylis-Hillman adducts
Porto, Ricardo S.,Vasconcellos, Mario L. A. A.,Ventura, Elizete,Coelho, Fernando
, p. 2297 - 2306 (2007/10/03)
The results of a highly diastereoselective epoxidation of allylic diols derived from Baylis-Hillman adducts are reported. The formation of an intramolecular hydrogen bond seems to be responsible for the high anti diastereoselection obtained in this epoxid
Diastereoselective heterogeneous catalytic hydrogenation of Baylis- Hillman adducts
Mateus, Cristiano R.,Almeida, Wanda P.,Coelho, Fernando
, p. 2533 - 2536 (2007/10/03)
We describe herein our results concerning a highly diastereoselective heterogeneous hydrogenation of Baylis-Hillman adducts obtained from aromatic aldehydes. The results obtained are complementary to those already described for homogeneous catalytic hydro
1,4-asymmetric induction in the chromium(II)- and indium-mediated coupling of allyl bromides to aldehydes
Maguire, Robert J.,Mulzer, Johann,Bats, Jan W.
, p. 6936 - 6940 (2007/10/03)
A series of allyl bromides bearing an ethereal stereogenic substituent at C-2 were synthesized from methyl acrylate. These were coupled with a range of aldehydes under chromium(II) chloride-mediated conditions to afford syn-4-alkoxyalkan-1-ols in good yie
1,3-Dipolar Cycloadditions to Baylis-Hillman Adducts: Rationale for the Observed Diastereoselectivity
Annunziata, Rita,Benaglia, Maurizio,Cinquini, Mauro,Cozzi, Franco,Raimondi, Laura
, p. 4697 - 4706 (2007/10/02)
Diazomethane and benzonitrile oxide cycloadditions were performed on Baylis-Hillman adducts derived from methyl acrylate and aldehydes (β'-alkoxy-α,β-unsaturated esters).The reactions proceed in good chemical yields, and their stereochemical outcome can b
A simple route to α-substituted-β-amino ester precursors of carbapenem antibiotics
Perlmutter,Tabone
, p. 6515 - 6522 (2007/10/03)
A three-step process is presented for the preparation of α-substituted-β-amino esters which can serve as precursors to a key intermediate in carbapenem synthesis. The pivotal reaction in this sequence involves a highly diastereoselective conjugate addition reaction. Two series of alkenoates bearing a stereogenic substituent attached to C2 were prepared and their conjugate addition reactions with benzylamine studied under several different sets of conditions. Conjugate addition of benzylamine to alkenoates 7a and 7d, in methanol at room temperature, gave adducts 8a and 8d with virtually complete anti-diastereoselectivity. These two β-amino esters bear the correct relative stereochemistry and side chain to serve as precursors for carbapenem antibiotic synthetic intermediates. The role of the allylic substituents of the alkenoates 7a-e in determining the stereochemical outcome of these additions is discussed. These conjugate additions were explored further by the preparation and conjugate addition reactions of the α,β-disubstituted alkenoates 15a and 15b. It was found that the presence of a β-substituent led to a dramatic reduction in yield although the same anti-diastereoselectivity was maintained. The relative stereochemistry of the adducts was established by examination of the relevant coupling constants in the 1H NMR spectra of their tetrahydro-1,3-oxazine derivatives.
