SYNFORM ISSUE 2010/4

Synthesis 2010; 2010: A33-A38
DOI: 10.1055/s-0029-1219633



© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

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Process Chemistry in the Pharmaceutical Industry, Vol. 2: Challenges in Ever-Changing Climates

Synthesis 2010; 2010: 1058-1058
DOI: 10.1055/s-0029-1218689



© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

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A Concise Synthesis of (S)-2-(Fluorodiphenylmethyl)pyrrolidine: A Novel Organocatalyst for the Stereoselective Epoxidation of α,β-Unsaturated Aldehydes

Synthesis
DOI: 10.1055/s-0029-1218636



Abstract

A concise synthesis of ()-2-(fluorodiphenylmethyl)pyrrolidine from cheap, commercially available starting materials is described. Pertinent features of this synthetic route include ease of synthesis, facile purification steps, and an operationally simple deoxy­fluorination step to install the C-F bond.
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© Georg Thieme Verlag Stuttgart ˙ New York

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Peptide-Catalyzed Conjugate Addition Reactions of Aldehydes to Nitroolefins

Synthesis
DOI: 10.1055/s-0029-1218651



Abstract

The tripeptide H--Pro-Pro-Glu-NH is an efficient catalyst for conjugate addition reactions of aldehydes to nitroolefins. Chiral γ-nitroaldehydes are obtained in excellent yields and stereoselectivities in the presence of as little as 1 mol% of the tripeptide catalyst. Under further optimized reaction conditions the product was obtained in essentially perfect stereoselectivity (/, >99:1, 99% ee).
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Stereoselective Total Synthesis of Cladospolide A

Synthesis
DOI: 10.1055/s-0029-1219236



Abstract

A simple and highly efficient stereoselective total synthesis of cladospolide A, a polyketide natural product, has been achieved. The synthesis involves stereoselective zinc-mediated allylation, pivotal aldol coupling, and ring-closing metathesis. The pivotal aldol coupling is used for the first time for macrolide construction and provides an effective alternative to Yamaguchi macrolactonization.
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Lateral Lithiation of N′-(2-Methylbenzyl)-N,N-dimethylurea and N-(2-Methylbenzyl)pivalamide: Synthesis of Tetrahydroisoquinolines

Synthesis
DOI: 10.1055/s-0029-1219277



Abstract

Lithiation of ′-(2-methylbenzyl)-,-dimethylurea and -(2-methylbenzyl)pivalamide with two mole equivalents of -butyllithium at -78 ˚C takes place on the nitrogen and on the methyl group at position 2. The lithium reagents thus obtained react with a variety of electrophiles to give the corresponding side-chain-substituted derivatives in high yields. Dehydration of the products obtained from reactions with carbonyl compounds in some cases gives the corresponding tetrahydroisoquinolines in excellent yields, while in other cases dehydration takes place within the substituted side chain to produce the corresponding alkenes in excellent yields.
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Concise Synthesis of Pyrimido-azocine Derivatives via Aza-Claisen Rearrangement and Intramolecular Heck Reaction

Synthesis
DOI: 10.1055/s-0029-1219276



Abstract

An expedient approach involving BF˙OEt-catalyzed aza-Claisen rearrangement and palladium-catalyzed intramolecular Heck reaction for the synthesis of pyrimidine-fused azocine derivatives is described. The mechanistic interpretation of the plausible mode of cyclization is also described.
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Highly Efficient Cs2CO3-Catalyzed 1,4-Addition of Me3SiCN to Enones with Water as the Additive

Synthesis
DOI: 10.1055/s-0029-1218653



Abstract

A facile and efficient 1,4-addition of MeSiCN to enones has been achieved with perfect regioselectivity using CsCO as catalyst. Thus, with 0.5 mol% of CsCO and 4 equivalents of HO as the additive excellent yields (81-99%) of β-cyanoketones are obtained within one to five hours. Both aromatic and aliphatic enones are found suitable substrates for this protocol.
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Cobalt-Catalyzed Generation of 1,4-Dienes as Synthons for 1,3-Dicarbonyl Compounds and Their Application in Natural Product Syntheses

Synthesis
DOI: 10.1055/s-0029-1219278



Abstract

The cobalt-catalyzed 1,4-hydrovinylation of alkenes with 1,3-dienes and the cobalt-catalyzed Diels-Alder reaction of alkynes with 1,3-dienes lead to acyclic and cyclic 1,4-dienes, respectively. These products can be transformed into 1,3-dicarbonyl functional groups by ozonolysis or alternative carbon-carbon double bond cleaving reactions. The application towards the synthesis of hepialone and a pyranone-type lipid from Vanilla beans is described.
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A New Synthesis of Functionalized 2,2′-Biimidazoles

Synthesis
DOI: 10.1055/s-0029-1218655



Abstract

A new two-step synthesis of N,N′-disubstituted 2,2′-biimidazoles from bisimidoyl chlorides is reported. The bisimidoyl chlorides react smoothly with (2,2-dimethoxyethyl)amine to give bisamidines that are subsequently cyclized to give the corresponding biimidazoles.
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