Florence M. C. de Farias

Formal synthesis of (-)-vallesamidine a 2;2;3-trialkylindoline alkaloid

Abstract (S)-(+)-2-ethyl-2[2′-carboxymethyl]cyclopentanone 6 was prepared regio- and enantioselectively (ee = 90%) by “deracemizing alkylation” of the chiral imine 5 with methylacrylate. Compound 6 was transformed into the bicyclic imine (R)-(+)- 3 . This intermediate was used by Heathcock, in the racemic form, to the total synthesis of (±)-Vallesamidine 1 , a 2,2,3-trialkylindoline alkaloid.

Control of diastereoselectivity in the aldolization of methyl phenylacetate

Abstract The aldolization of methyl phenylacetate with benzaldehyde in several conditions was studied. While the use of LDA in THF–HMPA gave the anti -aldol, the dibutylboron triflate furnished the syn -aldol in high diastereoselectivity ( syn : anti =97:3).

The 1,4-addition of organometallic reagents to enoates derived from pinanediol

Abstract The complex-induced, proximity effect-promoted 1,4-addition of RCu·BF3 and R2CuLi to enoates derived from (−)-pinanediol leads to adducts with the opposite sense of chirality (up to 98% d.e.).

Stereoselective Mannich reaction of camphor titanium enolate

Abstract The Mannich reaction of the titanium enolate derived from d -camphor with different electrophiles leading stereoselectively to the exo adduct has been performed using a attractive procedure.

A pinene-based chiral auxiliary for α-alkylation and aldol reactions: an unexpected effect of the base on the stereoselectivity

Abstract While the use of LDA as the base in the kinetic deprotonation step of the pinene-based ester 3 led to moderate diastereoselectivities in α-alkylation and aldol reactions, the use of LICA and LTMP resulted in a reduction in the anti / syn ratios and π-facial selectivities.

Molecular modeling of a phenyl-amidine class of NMDA receptor antagonists and the rational design of new triazolyl-amidine derivatives.

Recently, many efforts have been made to develop N‐methyl‐d‐aspartic acid receptor antagonists for treating different pathological conditions such as thrombo‐embolic stroke, traumatic head injury, Huntington’s, Parkinson’s, and Alzheimer’s diseases). However, as side‐effects limit the use of most antagonists, new drugs are still required. In this work, we performed a (quantitative) structure‐activity relationship analysis of 17 phenyl‐amidine derivatives (1a–1q), reported as N‐methyl‐d‐aspartic acid receptor antagonists, and used this data to rationally design the triazolyl‐amidines. The best (quantitative) structure‐activity relationship model constructed by multiple linear regression analysis presented high data fitting (R = 0.914) was able to explain 83.6% of the biological data variance (R2 = 0.836), presented a satisfactory internal predictive ability (Q2 = 0.609) and contained the descriptors (EHOMO, Ovality and cLogP). Our assays confirmed that glutamate promotes an extensive cell death in avian neurons (77%) and 2a and 2b protected the neurons from the glutamate effect (from 77% to 27% and 45%, respectively). The results of neurotoxicity and cytotoxicity on Vero cells suggested the favorable profile of 2a and 2b. Also, the molecular modeling used to predict the activity, the interaction with the receptor and the pharmacokinetic and toxicity of the triazolyl‐amidines pointed them as a promising class for further exploration as N‐methyl‐d‐aspartic acid receptor antagonists.

The regio- and stereoselective oxyamination of pinenes and camphene

Abstract The osmium-induced vicinal oxyaminations of pinenes and camphene have been performed with high regio- and stereoselectivities.

A short asymmetric synthesis of 4,4-disubstituted-γ-butyrolactones from racemic 2-methylcyclohexanone in multigram scale

Abstract A short and efficient asymmetric synthesis of both enantiomers (R)-1a–c and (S)-1a–c has been performed on a large scale and with high stereoselectivities from 2-methylcyclohexanone.

Construction of a Molecular Model: A Mathematical-Chemical Interdisciplinary Approach in the Secondary Education

This paper presents the construction of molecular models from easily accessible materials as well as details of the geometrical and trigonometric theories that support it. Its aim is to allow a chemical-mathematical interdisciplinary approach to the subject, under the assumption that knowledge of the molecular geometrical shape, as well as of biand three-dimensional representations in chemistry, is supplied by the linguistic complements provided by the overlap between the theories of chemistry and mathematics.