ORGANOSULPHURATED CHEMISTRY

Author: SANZ CUESTA MARIA JESUS.
Year: 2004.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: UNIVERSIDAD AUTONOMA DE MADRID.
Place of preparation: UNIVERSIDAD AUTONOMA DE MADRID.

Summary: 1. Asymmetric Synthesis of [4] helicenoquinonas 1.1. The first objective in this Doctoral Thesis focused on the development of a method of synthesis that would allow access in general terms derivatives [4] helicenoquinona in enantioméricamente pure, whose stability configuracional was not known. 1.2. The synthesis is based on a domino reaction of Diels-Alder/eliminación pirolítica of sulfoxide and flavoring, which takes place when a 5-alquil-1, 2-dihidro-3-vinil-naftaleno becomes react with [(S ) S] -2-p-tolilsulfinil-1 ,4-benzoquinona. 1.3. A study of theoretical calculations carried out by Professor F. Maseras of ICIQ supported the experimental data of relative stability observed in [4] helicenos, depending on the volume estérico group rent in position 12. The theoretical studies conducted have established the following order for stability configuracional: tBu>> iPr>>>> OMe 2. Synthesis and reactions adding 4-hidroxi-5-sulfinil enoatos and enonas 2.1. The second objective relates to the proposed development of a method of synthesis of 4-hidroxi-5-sulfinil enoatos and enonas enantioméricamente cigars, and the study of their reactivity, in order to assess if their behavior was similar to that seen in p-quinoles-p-tolilsulfinilmetil replaced, which also possessed a fragment of -hidroxisulfóxido in its structure. Once settled the synthesis of these compounds were studied the reactions of adding different nucleotide: XMgR, AlR3, R2CuLi, Et2AlCN, etc. .. 2.2. The reagents organoalumínicos as AlMe3, whose low reactivity in the alkylation of esters and derivatives-hydroxy-, -insaturados has been checked, are transferred easily when aceptores Michael type oxygenated have a replacement in position, and a function of sulfur (sulfoxide or sulfone) in position, causing the carbinoles tertiary. This methodology synthesis carbinoles tertiary is compatible with the presence of conjugated double bonds, because there is no competition with the conjugate addition reaction. 2.3. Were obtained good selectivity in the addition of reagents copper on 4-hidroxi-5-sulfinilenoatos synthesized. The evolution of the reaction is dominated by the configuration of centers estereogénicos in the product line, as well as the reaction conditions to be submitted reagents. 3. Summaries of 4-aminotroponas 3.1. The third part of this work relates to the synthesis and study of derivatives 4-aminotropona from different p-quinaminas differently replaced. The compounds that have succeeded in synthesizing completely regiocontrolada. 3.2. It has developed a method regioselectivo synthesis 4-aminotroponas from p-quinaminas aril [sulfinil (or sulfonil) methyl] and alkyl [sulfinil (or sulfonil) methyl] replaced easily accessible from N-BOC anilides in just three steps synthesis: electrochemical oxidation to synthesize acetals of p-benzoquinonimina precursors addition of anion lithium derivative alquilarilsulfóxido (or sulfone) or alquilalquilsulfóxido (or sulfone) on the group imina and treatment NaH.

Author: FERNÁNDEZ IBÁÑEZ M. ANGELES.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: UNIVERSIDAD AUTÓNOMA DE MADRID.
Place of preparation: UNIVERSIDAD AUTÓNOMA DE MADRID.

Summary: From the results obtained in this Doctoral Thesis on the influence exerted by the group sulfinilo in various reactions addition nucleófila to carbonyls four links of chiral center (induction 1.5), one can draw the following conclusions: 1-REACTION REDUCTION The reaction reduction DIBALH different -cetosulfóxidos passes with no estereoselectividad. However, in the presence of Yb (OTf) 3 are achieved high diastereoselectividades due to the formation of an eight-member chelate between the metal and oxígenos sulfinílico and carbonílico as pre-reduction. Using a hydride more voluminous, as L-Selectride leads to a high diastereoselectividad as a result of conformational restrictions on links with the carbonyl caused by their interactions with the group sulfinilo. 2-REACTION HIDROCIANACION The reaction hidrocianación in the presence of Et2AICN passes with very low estereoselectividad, which significantly increase the use of Yb (OTf) 3 as a catalyst. The combination of TMSCN / Yb (OTf) 3 provides a lower diastereoselectividad. The cianhidrinas sulfoxide obtained in this reaction can be transformed into the corresponding amides tioéter in soft conditions, due to the assistance anquimétrica group sulfinilo. 3-REACTION ALQUILACIÓN The alkylation reaction with different Alans passes with moderate diastereoslectividad and requires long reaction times to ensure that the conversion is complete. However, the use of mangesianos produces carbinoles with total diastereoselectividad, probably due to the formation of a chelate between magnesium and oxígenos sulfinílico and carbonílico, similar to that form in the presence of YB (OTf) 3 in the previous cases. Unfortunately, the conversion is observed in these reactions b aja because of the easy enolización of substrates of departure. 4-REACTION ALDÓICA OF MUKAIYAMA The reaction Mukaiyama between the (S) - [2 - (p-tolsulfinil) phenyl] acetaldehyde (3e) and different enolatos sililados of tioésteres in the presence of Yb (OTf) 3 passes with good diastereoselectividades. When used enolatos substituted position becomes totally controlling the configuration in carbon hidroxílico and regardless of the geometry of the double bond of enolato of departure, you get your diastereosómero anti-like majority. 5-REACTION HETERO DIELS-ALDER The reaction of (S) - [2 - (p-tolilsulfininil) phenyl] acetaldehyde (3e) in the presence of YB (OTf) 3 with different dienos structure similar to Danishefsky, leads to adduct HDA good diastereoselectividades. In cases that form two new chiral centers, is controlled entirely settings in the oxygenated carbon and a high level of induction at the center metínico. The mechanism by which passes the reaction is not reached, but by steps, thereby isolating the reaction intermediate. The reaction of losproductos obtained with Ni-Raney allows desulfinilación of substrates. Some of these reactions occur simultaneously reducing the system carbonílico, unsaturated good diastereoselectividad.

Author: GARCIA GARCIA PILAR.
Year: 2005.
University: SALAMANCA [www.usal.es].
Place of defense: FACULTAD DE CIENCIAS QUIMICAS.
Place of preparation: FACULTAD DE CIENCIAS QUIMICAS.

Summary: This paper has developed a new synthetic methodology for obtaining stereoselective of ciclopropanoles and ciclopropilaminas enantioméricamente cigars. This methodology consists of a reaction replacement nucleofílica intramolecular using sulfones alílicas as products of departure. The analysis of the various factors influencing the reaction ciclación (base employee groups protectors, outgoing group, estereoquímica twice link in the product partidaâ |) has enabled the preparation of ciclopropilvinilsulfonas of stereoselective manner. We have also studied various aspects of the reactivity of ciclopropilvinilsulfonas obtained such as reordering vinilciclopropano-ciclopenteno, hydrogenation reaction and subsequent hydrolysis of the group or protective reaction epoxidación nucleofílica. The functional group vinilsulfona present at the ciclopropilvinilsulfonas has enabled the synthesis of amino acids conformation restricted. Specifically, there are analogues glutamic acid, used as a key step an addendum Michael type of reagent Schà ¶ llkopf to vinilsulfona. A study of molecular modeling shows that the minimum energy conformations of the two analogues obtained, are very similar to those conformations that the glutamic acid takes in metabotropic receptors and ionotrópicos respectively. Ease of desprotonación in the group vinilsulfona, has been used for the preparation of other amino acids conformacionalmente restricted. To which had conducted a study of the reaction of adding vinilsulfonas litiadas to bencilimina derived from R-gliceraldehído.

Author: DÍAZ ÁLVAREZ JESÚS.
Year: 2005.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: This thesis demonstrates the involvement of structures tautoméricas on the properties of the compounds mesoiónicos, taking as an example the 2-alquiltioisomà ¼ nchnonas. The development work begins with the exploration of a new and simple overview of 2-alquiltioisomà ¼ nchnonas and subsequently with the computational and spectroscopic study of possible tradeoffs tautoméricos (and atropisoméricos) that can be displayed. It describes a balance tautomérico general systems 2-alquiltioisomà ¼ nchnonas and 2-alquilidén-1 ,3-tiazolidín-4-onas, which is observable espectroscópicamente in solution. The crystallization of tiazolidinas Pure has allowed its characterization in the solid state. Moreover, if the structure includes sustituyeres N-arílicos orto-disustituidos, there is also restricted rotation around this link. When they react halides of alfa-haloácidos tioformanilidas, instead of tiocarboxanilidas to access to tioisomà ¼ nchnonas not replaced in position 2, was obtained in exchange tioimidas mixed in which there has been the acilación nitrogen, and which fail to evolve to tioisomà ¼ nchnonas under the reaction conditions. We have also explored the reactivity of 2-alquiltioisomà ¼ nchonas in relation to various targets. The 2-alquiltioisomà ¼ nchonas react generating unions CC with electrófilos as chlorides of acilo alifácticos, isocyanates and isothiocyanates, to 2-acil, 2-carboxamido- or 2-tiocarboxamido-alquilidén-1 ,3-tiazolidín-4-onas respectively. In contrast react with chlorides of acilo aromatic producing 2-diacilmetiltioisomà ¼ nchonas. Moreover, bromine generates halohidrina. The 2-alquiltioisomà ¼ nchnonas react with nucleotide as alcohols, thiol, carboxylic acids, and so on. The result of the reaction can be streamlined in a process that began with the addition to the double bond 3exocíclico system 2-alquilidén-1 ,3-tiazolidín-4-ona. With alcohol and thiol yields the corresponding 2-alcoxi or tioalcoxi-tiazolidón-4-onas. The reaction is highly estereoslectiva, the attack occurred at the opposite side to which occupies the phenyl to C5. With acids carboxílcios is obtained 2-hidroxia-tiazolidín-4-ona, reached after the reaction and subsequent hydrolysis. Finally, ammonia was isolated one 2-tiolamida as a product of evolution of the initial adult Moreover, 2-alquiltioisomà ¼ nchnonas reaction as hetero mesoiónicos processes cicloadición 1,3-dipola face alquenos and acetilenos. Also the reaction with chloride acriloílo, which is a good electrífolo and a good dipolarófilo, evolves by a cicloadición dipolar, and not through a condensing electróflio / nucleófilo. These results demonstrate for the first time that it is possible to develop a chemistry different for each of the tautómeros in equilibor a system memsoiónico. Finally, the results achieved by rationalizing calculations semiempíricos and DFT. Lastly include resultdos theoretical reactions cicloadición 1,3-dipolares between different nitronas chiral and dimetilvinilborano realizaod at Cambridge University, in these calculations are studying how it affects the esteroselectividad of reaction the effect of substituents on the nitronas Cycle and how is puedne obtnere large estereoslectividades for nitronas not cyclical. There has been studied the reactions of oxidation, vinilboración and ciclación that can compete with cicloadición, finding as the latter is always favored some riddles activation much lower than those corresponding to the reaction of other roads.