Stereocontrolled Addition of Scrambling -Sulfinyl Carbanions: Easy Access to Homopropargylamines and α-Allenylamines.

An unprecedented behavior of -sulfinylpropargyl carbanions in the presence of optically active sulfinylimines affords two different families of compounds: this peculiar chemodivergency is importantly affected by the nature of the employed base, and assisted by the configuration of the electrophile, displaying no alteration in the stereocontrol of both reactions. α-Allenylamines are formed exclusively, using -sulfinyl aldimines as electrophiles, while homopropargylamines result when -sulfinyl aldimines are employed.

Asymmetric [2,3]-Wittig Rearrangement: Synthesis of Homoallylic, Allenylic, and Enynyl α-Benzyl Alcohols.

A highly stereoselective [2,3]-Wittig rearrangement of allylic and propargylic ethers controlled by a chiral sulfoxide moiety is presented. The activation provided by the sulfoxide at the remote ortho position allows the rearrangement of less-activated and unexplored benzylic carbanions. Thus, this general methodology gives access to the asymmetric synthesis of homoallylic, enynyl, and allenylic α-benzyl alcohol derivatives.

Development and Application of Asymmetric Organocatalytic Mukaiyama and Vinylogous Mukaiyama-Type Reactions.

Organocatalysis is a growing area that is benefiting from advances in many fields. Its implementation has begun in areas such as supramolecular chemistry, organic chemistry and natural product synthesis. While a considerable number of important publications in the field of organocatalytic Mukaiyama-type additions have been reported, they are yet to be fully covered in a review.

Asymmetric Synthesis of Secondary and Tertiary Propargylic Alcohols by Umpolung of Acetylenic Sulfones and ortho-Sulfinyl Carbanions.

The generation of diastereomerically enriched secondary benzyl propargyl alcohols by the asymmetric addition of ortho-sulfinylbenzyl carbanions to sulfonylacetylene derivatives via formation of a Csp-Csp bond is described. This reaction proceeds through an unusual α-attack (anti-Michael addition) of the ortho-sulfinylbenzyl carbanions, followed by elimination of the arylsulfonyl moiety. The scope of this alkynylation reaction is also discussed.

The relationship between regular sports participation and vigilance in male and female adolescents.

The present study investigated the relationship between regular sport participation (soccer) and vigilance performance. Two groups of male and female adolescents differentiated in terms of their sport participation (athletes, n = 39, and non-athletes, n = 36) took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level.

A straightforward alkynylation of Li and Mg metalated heterocycles with sulfonylacetylenes.

Coupling of alkynyl moieties to heterocyclic rings, without using transition metals, can be easily performed by the reaction of aryl or heteroaryl sulfonylacetylenes with heteroaryl-Li compounds or their corresponding less reactive magnesium derivatives.

1,2-Dimeth-oxy-4-methyl-3-[(S)-p-tolyl-sulfin-yl]benzene.

In the title compound, C(16)H(18)O(3)S, the dihedral angle between the benzene rings is 75.48 (8)°. The absolute configuration at the stereogenic S-atom center was determined as S.

Asymmetric synthesis of (S)-(-)-xylopinine. Use of the sulfinyl group as an ipso director in aromatic SE.

Optically pure (S)-(-)-xylopinine 2 was prepared in three steps in 52% overall yield. Thus, condensation of the carbanion derived from (S)-4 with the (S)-(E)-sulfinylimine 5 gave a 2:1 mixture of tetrahydroisoquinolines 6a and 6b, differing only in configuration at sulfur. N-Desulfinylation of this mixture gave the diastereomeric sulfoxides which, without separation, were converted into (S)-(-)-xylopinine (2) with loss of the sulfinyl moieties under Pictet-Spengler conditions.

Methyl sulfinates as electrophiles in Friedel-Crafts reactions. Synthesis of aryl sulfoxides.

The Friedel-Crafts reaction of methyl alkyl- and arylsulfinates with aromatic systems, activated by one or more electron-donating substituents (OH, OMe, NHR, NR(2)), provides alkyl aryl and diaryl sulfoxides under mild conditions and in moderate to good yields. The very high regioselectivity usually observed in these sulfinylation reactions is rationalized on the basis of a Wheland intermediate having a trigonal bypyramidal structure in which steric and electronic interactions are significant factors strongly destabilizing the attack to the ortho positions.

1,3-dipolar cycloaddition of diazoalkanes to (S)-(+)-3-[(4-methylphenyl)sulfinyl]-5,6-dihydropyran-2-one. Synthesis of optically pure cyclopropanes by denitrogenation of sulfinyl and sulfonyl pyrazolines.

The addition of diazomethane and diazoethane to enantiopure (S)-(+)-3-[(4-methylphenyl)sulfinyl]-5,6-dihydropyran-2-one (3) afforded the corresponding pyrazolines 4 and 6-exo in good yields and with almost complete pi-facial selectivity. When the reaction is effected in the presence of Yb(OTf)(3), the facial selectivity is inverted to give the pyrazolines 5 and 7-exo. The denitrogenation of optically pure sulfinyl pyrazolines 4-7-exo into the corresponding cyclopropanes with Yb(OTf)(3) occurred with complete retention of configuration but moderate chemoselectivity and yields.

Monoalkylation of primary amines and N-sulfinylamides.

An efficient monoalkylation of primary amines with primary or secondary alcohols catalyzed by Ra-Ni under mild conditions is described.