Derivatives of the natural occurring and inexpensive terpene (R) -limonene were synthetized and completely characterized. Starting from internal olefin epoxidation, followed by epoxide opening with sodium azide and azide reduction with LiAlH4, two chiral amino-alcohols were obtained. The amino-alcohols were reacted with three different aldehydes, generating six new imino-alcohols, two of them yielding crystals suitable for X-ray diffraction characterization. The reduction of four of these compounds with LiAlH4 led to new amino-alcohols. All derivatives were obtained with good overall yields through simple reaction protocols.

The stereochemical control in the generation of new stereogenic centers is of paramount importance in organic chemistry. In this context, diastereoselective additions to carbonyl compounds bearing a stereogenic center at the α-position are of particular importance, since an increase in molecular complexity can be achieved by constructing a new bond, together with the introduction of a new stereocenter. Despite the relevance of the topic, it is discussed only briefly in several of the most popular organic chemistry textbooks, or not discussed at all. The present article intends to discuss the evolution of stereochemical models for 1,2-induction and present to students a tool to understand and predict the stereochemical outcome of addition of nucleophiles to aldehydes and ketones bearing a stereogenic center at the α-position.

In the present study, we describe the synthesis of alkylseleno carbohydrates with different sugar scaffolds and the evaluation of their antioxidant activity profile. A compound possessing a C8 alkyl chain presented the best results in the free radical scavenging activity.

A transmetalação entre boro e zinco apresenta uma grande importância para diversas aplicações em síntese orgânica, uma vez que permite a formação de novas ligações carbono-carbono entre reagentes organometálicos e espécies eletrofílicas. A arilação direta de aldeídos e, mais raramente de cetonas, de maneira catalítica e enantiosseletiva, empregando catalisadores quirais, têm sido descrita recentemente. Os diaril metanóis opticamente enriquecidos, obtidos nessas reações são precursores valiosos para a síntese de moléculas bioativas. O presente trabalho apresenta uma revisão sobre essa crescente área de atuação e destaca alguns dos desafios que ainda permanecem.

The transmetalation between boron and zinc is of great importance for application in organic synthesis, since it allows the formation of new carbon-carbon bonds between organometallic units and electrophiles. The direct arylation of aldehydes or more scarcely ketones, in a catalytic, enantioselective manner using chiral catalysts has been described recently. The enantiomerically enriched diarylmethanols obtained in these reactions are valuable precursors for important bioactive molecules. This review provides a synopsis of this ever-growing field and highlights some of the challenges that still remain.

Nesse trabalho descreve-se, pela primeira vez, um estudo comparativo sobre a atuação de oxazolinas quirais contendo calcogênio em suas estruturas em reação de alquilação alílica assimétrica, catalisada por paládio, do acetato de 1,3-difenil-2-propenila com malonato de dimetila. Diferenças no desempenho entre os análogos de enxofre, selênio e telúrio são observadas.

A comparative study about the ability of chiral chalcogen-containing oxazolines to act as chiral ligands in the palladium-catalyzed allylic alkylation of rac-1,3-diphenyl-2-propenyl acetate with dimethyl malonate is reported. Differences in the catalytic performance are observed with sulfur, selenium and tellurium analogues.