There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylation 3121 6.1.6. Alkylation 3121 6.1.7. Reformatsky-Type Reaction 3122 6.1.8. Direct Aldol Reaction 3122 6.1.9. Mukaiyama Aldol Reaction 3124 6.1.10. Hydrogen Cyanide Addition 3125 6.2. Pinacol Coupling 3126 6.3. Wittig Reactions 3126 7. Reaction of R,â-Unsaturated Carbonyl Compounds 3127

Organic Reactions in Aqueous Media with a Focus on Carbon−Carbon Bond Formations: A Decade Update

Asymmetric multicomponent reactions involve the preparation of chiral compounds by the reaction of three or more reagents added simultaneously. This kind of addition and reaction has some advantages over classic divergent reaction strategies, such as lower costs, time, and energy, as well as environmentally friendlier aspects. All these advantages, together with the high level of stereoselectivity attained in some of these reactions, will force chemists in industry as in academia to adopt this new strategy of synthesis, or at least to consider it as a viable option. The positive aspects as well as the drawbacks of this strategy are discussed in this Review.

Asymmetric multicomponent reactions (amcrs): the new frontier

Stereoselective organic reactions in water.

Functional π-Gelators and Their Applications

The reactivity of (Z)-2-phenyl-4-benzylidene-5(4H)-oxazolone 1 as dienophile in the Diels-Alder reaction with 1,3-butadiene and 2,3-dimethyl-1,3-butadiene is studied. The adducts obtained starting from the cycloaddition of 1 with both dienes are converted, through simple reactions into the conformationally restricted cyclic amino acids cis-1-amino-2-phenylcyclohexanecarboxylic acid 6 and 1-amino-c-4,c-5-dimethyl-t-2-phenyl-r-1-cyclohexanecarboxylic acid 10 , analogues of phenylalanine.

Synthesis of New Conformationally Rigid Phenylalanine Analogues.

The Crucial Role of S-oxidation State on the Selectivity and Reaction Rate of the 1,3-Dipolar Cycloaddition of Azomethine Ylides and Homochiral Thiazolines

SHORTENED TITLE: HPLC resolution of cis-and trans-β-phenylproline ABSTRACT The preparation of all four stereoisomers of the proline analogue that bears a phenyl group attached to the β carbon either cis or trans to the carboxylic acid (cis-and trans-β-phenylproline, respectively) has been addressed. The methodology developed allows access to multigram quantities of the target amino acids in enantiomerically pure form and suitably protected for use in peptide synthesis. Racemic precursors of cis-β-phenylproline and trans-β-phenylproline were prepared from easily available starting materials and subjected to HPLC enantioseparation. Semi-preparative columns (250 mm × 20 mm) containing chiral stationary phases based on amylose (Chiralpak ® IA) or cellulose (Chiralpak ® IC) were used, respectively, for the resolution of the cis-and trans-β-phenylproline precursors.

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Access to Enantiomerically Pure cis- and trans- β-Phenylproline by HPLC Resolution

This research was made possible by the generous financial support of the Comision Asesora de Investigacion Cientifica y Tecnica (project number PB85-0335). Maria P. Bueno would like to express her gratitude to the Diputacion General de Aragon and Paula Charro to the Instituto de Estudios Riojanos for a grant.

Natural Amino Acids as Chiral Auxiliaries in Asymmetric Diels-Alder Reactions.

The authors thank Consejo Nacional de Ciencia y Tecnologia (CONACYT) for financial support through projects 181816 and 248868, the Ministerio de Ciencia e Innovacion – FEDER (grant CTQ2010-17436), and the Gobierno de Aragon-FSE (research group E40).

Carlos Cativiela

Papers

Synthesis of New Conformationally Rigid Phenylalanine Analogues.

The Crucial Role of S-oxidation State on the Selectivity and Reaction Rate of the 1,3-Dipolar Cycloaddition of Azomethine Ylides and Homochiral Thiazolines

Access to Enantiomerically Pure cis- and trans- β-Phenylproline by HPLC Resolution

Natural Amino Acids as Chiral Auxiliaries in Asymmetric Diels-Alder Reactions.

First Synthesis of (R)- and (S)-1,2,3,4-Tetrahydroisoquinoline-3-phosphonic Acid (TicP) Using a Pictet-Spengler Reaction.