Tietze reaction

In order to study any chemoselectivity influences of microwave irradiation on the domino Knoevenagel/hetero-Diels-Alder process (the so-called Tietze reaction), Raghunathan and coworkers [31a] investigated the transformation of 4-hydroxy coumarins (10-85) with benzaldehydes 10-86 in EtOH to afford pyrano[2,3-c]cou-marin 10-87 and pyrano[2,3-b]chromone derivatives 10-88. Normal heating of 10-85a and 10-86a at reflux for 4h gave a 68 32 mixture of 10-87a and 10-88 in 57% yield, whereas under microwave irradiation a 97 7 mixture in 82% yield was obtained. Similar results were found using the benzo-annulated substrates 10-85b and 10-86b. 

Figure 1 A hypothetical scheme to illustrate the Tietze reaction. DTNB is represented as < >SS(t> and reacts with GSM to form the mixed disulphide GSS< >. This appears to be a substrate for glutathione reductase and is reduced to regenerate GSM, which then enters another round with DTNB, continuing to produce the yellow anion TNB at a rate that is dependent on the initial concentration of GSM.

Domino reactions, in which a series of carefully planned reactions occurs in a single vessel, used to prepare complex biologically active organic compounds (Hall, 1994 Tietze, 1995). 

Tietze, L. F. (1995). Domino Reactions in Organic Synthesis. Chemistry dl Industry (19 June), 453-57. 

Tietze et al. investigated the Diels-Alder reaction between 44 and 2-methylbut-2-ene at the B3-LYP/6-31G level (Scheme 30) [98EJ02733]. 

The inverse electron-demand catalytic enantioselective cycloaddition reaction has not been investigated to any great extent. Tietze et al. published the first example of this class of reaction in 1992 - an intramolecular cycloaddition of heterodiene 42 catalyzed by a diacetone glucose derived-titanium(IV) Lewis acid 44 to give the cis product 43 in good yield and up to 88% ee (Scheme 4.31) [46]. 

Tietze LF, Haunert F (2000) Domino reactions in organic synthesis. An approach to efficiency, elegance, ecological benefit, economic advantage and preservation of our resources in chemical transformations. In Vogtle F, Stoddart JF, Shibasaki M (eds) Stimulating concepts in chemistry. Wiley-VCH, Weinheim, p 39... 

Tietze L. F., Modi A. Multicomponent Domino Reactions for the Synthesis of Biologically Active Natural Products and Drugs Med. Res. Rev. 2000 20 304-322 Keywords Diels-Alder reactions... 

Tietze L. E., Kettschau G., Gewert J. A., Schuffenhauer A. Hetero-Diels-Alder Reactions of l-Oxa-l,3-Bntadienes Curr. Org. Chem. 1998 2 19 62... 

Tietze L. F., Kettschau G. Hetero Diels-Alder Reactions in Organic Chemistry... 

Tietze L. F. Domino-Reactions the Tandem-Knoevenagel-Hetero-Diels-Alder Reaction and Its Application in Natural Product Synthesis J. Heterocycl. Chem. 1990 27 47-69... 

Tietze, L.R Rackelmann, N. (2004) Domino Reactions in the Synthesis of Heterocyclic Natural Products and Analogs. Pure and Applied Chemistry, 76, 1967-1983. 

Tietze, L.F. Lieb, M.E. (1998) Domino Reactions for Library Synthesis of Small Molecules in Combinatorial Chemistry. Current Opinion in Chemical Biology, 2, 363-371. 

Tietze, L. F., Pfeiffer, T., Schuffenhauer, A., 1998, Stereoselective Intramolecular Hetero Diels-Alder Reactions of Cyclic Benzylidenesulfoxides and DFT Calculations on the Transition Structures , Eur. J. Org. Chem., 2733. 

Tietze, L.F., Brasche, G. and Gericke, K.M. (2006) Domino Reactions in Organic Synthesis, Wiley-VCH Verlag GmbH, Weinheim. 

Domino Reactions in Organic Synthesis. Lutz F. Tietze, Gordon Brasche, and Kersten M. Gericke Copyright 2006 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527 29060-5... 

One of the first enantioselective transition metal-catalyzed domino reactions in natural product synthesis leading to vitamin E (0-23) was developed by Tietze and coworkers (Scheme 0.7) [18]. This transformation is based on a Pdn-catalyzed addition of a phenolic hydroxyl group to a C-C-double bond in 0-20 in the presence of the chiral ligand 0-24, followed by an intermolecular addition of the formed Pd-spe-cies to another double bond. 

L. F. Tietze, F. Haunert, Domino Reactions in Organic Synthesis. An Approach to Efficiency, Elegance, Ecological Benefit, Economic Advantage and Preservation of our Resources in Chemical Transformations, in M. Shibasaki, J. F. Stoddart and F. Vogtle (Eds.), Stimulating Concepts in Chemistry, Wiley-VCH, Weinheim, 2000, pp. 39-64 (d) L. F. Tietze, A. Modi, Med. Res. Rev. 2000, 20, 304-322 (e) L. F. Tietze, M. E. Iieb, Curr. Opin. Chem. Biol. 

Other valuable substrates for the domino Knoevenagel/hetero-Diels-Alder reaction are chiral oxathiolanes such as 2-778, which are easily accessible by condensation of 2-thioacetic acid and a ketone in the presence ofpTsOH, followed by oxidation with hydrogen peroxide [390]. As described by Tietze and coworkers, the Knoevenagel condensation of 2-778 with aldehydes as 2-777 can be performed in... 

In addition to aldehydes and a-diketones, a-ketoesters can also be used in the domino process, as shown by Tietze and coworkers [396]. Reaction of methyl pyruvate 2-791 with dimethylbarbituric acid (2-747) and the enol ether 2-792 in the presence of trimethyl orthoformate (TMOF) and a catalytic amount of EDDA gave the cycloadduct 2-793 in 84% yield (Scheme 2.176). 

Another class of alkaloids recently synthesized by Tietze and coworkers using a three-component domino Knoevenagel/hetero-Diels-Alder reaction included the Ipecacuanha alkaloids such as emetine (2-798) [402], and the Alangium alkaloids such as tubulosine (2-799) [403]. Both types belong to the group of tetrahydroi-soquinoline alkaloids, and are formed in Nature from dopamine and the monoter-... 

A combination of a Sakurai reaction [447] as the first step with an ene reaction has been developed by Tietze and coworkers for the synthesis of steroids [448]. These studies are discussed in Chapter 4. 

Tietze and coworkers [117] also used a metallo-ene reaction as the initiating step for the synthesis of the BCD-ring portion of steroids, which is then followed by a carbonyl-ene reaction. 

In transition metal-catalyzed domino reactions, more than one catalyst is often employed. In Tietze s definition and the classification of domino reactions, no distinction has been made between transformations where only one or more transition metal catalyst is used for the different steps, provided that they take place in a chronologically distinct order. Poli and coworkers [13] differentiated between these processes by calling them pure-domino reactions (which consisted of a single catalytic cycle driven by a single catalytic system) or pseudo-domino reactions . The latter type was subdivided into ... 

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