Ultrasound in Baylis–Hillman reactions with aliphatic and aromatic aldehydes: scope and limitations

Coelho, Fernando; Almeida, Wanda P.; Veronese, Demetrius; Mateus, Cristiano R.; Lopes, Elizandra C. Silva; Rossi, R; Silveira, Gabriel P. C.; Pavam, Cesar Henrique

doi:10.1016/s0040-4020(02)00822-0

Cited by 120 publications

(75 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This was accomplished using our well-established methodology described some years ago (Scheme 2). 13 In the sequence, the MBH secondary hydroxyl group was silylated to afford the protected MBH adducts (15)(16)(17) in good yields. Finally, silylated adducts 15-17 were chemoselectively reduced in the presence of DIBAL-H (diisobutylaluminium hydride) at -72 ºC, to afford the allylic diols 18-20, in overall yields ranging from 67 up to 72% (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…The 1 H and 13 C NMR spectra were recorded on a Varian Gemini BB-300 at 300 and 75.5 MHz, Bruker 250 at 250 and 62.5 MHz and on an Inova instrument at 500 and 125 MHz, respectively. The mass spectra (MS) were recorded using a Micromass (Manchester-UK) ESI-QqTOF (electrospray ionization quadrupole time-of-flight) with high resolution on the TOF mass analyzer and using a Premier-Waters GC/MS GCT EI-TOF, also with high resolution.…”

Section: Methodsmentioning

confidence: 99%

“…10 Our approach is based on a diastereoselective reductive amination of the 2-oxo-1,3-propanediol derivatives (9)(10)(11), that are easily prepared from double bond ozonolysis of an allylic diol. The latter is promptly prepared by chemoselective ester reduction of Morita-Baylis-Hillman adducts (12)(13)(14) after silylation of the secondary hydroxyl group. The retrosynthetic analysis is depicted below (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the analysis of the 1 H NMR spectra for all nitrogenated compounds showed a characteristic doublet at 6.50 ppm attributed to the secondary amide hydrogen and a second doublet (ranging from 5.14 to 5.29 ppm) attributed to the carbinolic proton. The analysis of the 13 C NMR spectra of these compounds shows signals around 75, 61 and 55 ppm, which were attributed to the secondary and primary carbinolic carbons and to the carbon bonded to the nitrogen, respectively.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Diastereoselective synthesis of substituted 2-amino-1,3-propanediols from Morita-Baylis-Hillman adducts

Paioti¹,

Rezende²,

Coelho³

2012

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Descrevemos nesse artigo uma abordagem diastereosseletiva, a partir de adutos de MoritaBaylis-Hillman (MBH), para a preparação de sistemas 2-amino-1,3-propanodióis substituídos com estereoquímica relativa anti. Estas unidades estruturais têm sido utilizadas como intermediárias para a síntese de diversas substâncias de interesse farmacológico e comercial. Nessa estratégia, os anti 2-amino-1,3-propanodióis foram facilmente preparados por ozonólise de dióis alílicos obtidos de adutos de MBH, seguido de uma aminação redutiva diastereosseletiva dos 2-oxo-1,3-propanodióis. Para demonstrar a utilidade desses aminodióis, eles foram transformados em oxazolidin-2-onas substituídas, que também foram utilizadas na determinação indireta da configuração relativa dos aminodióis.We report herein a new diastereoselective approach to substituted 2-amino-1,3-propanediols with anti relative stereochemistry from Morita-Baylis-Hillman (MBH) adducts. These structural moieties have been used as intermediates for the synthesis of several compounds with relevant pharmacological and commercial interest. In this strategy, substituted anti 2-amino-1,3-propanediols were readily prepared via ozonolysis of allylic diols obtained from MBH adducts, followed by a diastereoselective reductive amination of the substituted 2-oxo-1,3-propanediols. To demonstrate the synthetic utility of these aminodiols, they were transformed into substituted oxazolidin-2-ones, which were also used in the indirect determination of the relative stereochemistry of the aminodiols.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Diastereoselective synthesis of substituted 2-amino-1,3-propanediols from Morita-Baylis-Hillman adducts

Paioti¹,

Rezende²,

Coelho³

2012

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our approach for the synthesis of our target cyclopentenones 1 is based on a rhodium-catalyzed 1,4-addition 2 between a Morita-Baylis-Hillman adduct 3 and a suitable substituted boronate 4 , using a protocol described by Gênet et al (Sheme 1). Reagents and conditions: a) [Rh(cod)Cl]2 1-2 mol%; toluene/methanol ; reflux 3-8h; b) DIBAL-H; CH2Cl2; -78°C; 1h; c) CBr4; PPh3; CH2Cl2; 0°C -r.t.; 2h; d) Ethyl malonate, NaH; THF; 0°C; e) NaCl; H2O; DMSO; reflux 18h; f) Ethanol; NaOH 2N; reflux 3h; g) i. DMF; CH2Cl2; (COCl)2; 0°C -r.t.; 1h; ii.…”

Section: Resultsmentioning

confidence: 99%