Four-component reaction of cyclic amines, 2-aminobenzothiazole, aromatic aldehydes and acetylenedicarboxylate

• Hong Gao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 2934–2939, doi:10.3762/bjoc.9.330

• nitrogen-containing heterocycles [11][12][13][14][15][16]. In this hot research field, we also successfully developed a series of domino reactions containing primary amine, electron-deficient alkynes and the other components, and found several efficient synthetic protocols for versatile heterocycles and

• -dipoles very fast and in nearly quantitative yields [25][26]. But until now it seems that this kind of easily generated Huisgen 1,4-dipoles have not been utilized for the design of domino reactions. In continuation of our efforts to explore the practical applications of Huisgen 1,4-dipoles for the

• sequentially with other reagents to give cycloaddition products [1][2]. From then on much developments on the chemistry of Huisgen 1,4-dipoles have been achieved [3][4]. In the past few years, Huisgen 1,4-dipoles have been recognized as key components for designing practical multicomponent reactions and domino

Catalytic asymmetric tandem Friedel–Crafts alkylation/Michael addition reaction for the synthesis of highly functionalized chromans

• Jiahuan Peng and
• Da-Ming Du

Beilstein J. Org. Chem. 2013, 9, 1210–1216, doi:10.3762/bjoc.9.137

• stereogenic centers [1][2][3][4][5][6][7][8][9][10][11][12][13]. Newly developed tandem/domino reactions are increasingly applied in the synthesis of natural products and other biologically active compounds [14][15][16]. Dihydrocoumarins, chromans, and chromenes can be found in many natural products and

Synthesis of functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones] via one-pot four-component reactions

• Li-Juan Zhang,
• Qun Wu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 846–851, doi:10.3762/bjoc.9.97

• of a wide variety of heterocycles and pharmaceutical compounds [6][7][8][9][10][11]. Many domino reactions have been developed by trapping this kind of β-enamino ester with sequential adding of nucleophilic or electrophilic reagents to give versatile nitrogen-containing compounds and N,O-heterocycles

• [12][13][14][15][16][17][18][19][20][21][22][23]. Recently, Perumal and we have both developed an efficient synthetic procedure for functionalized spiro[indoline-3,4’-pyridines] by domino reactions of in situ generated β-enamino esters, isatin and malononitrile with triethylamine as the base catalyst

• [indoline-3,4’-pyridinones] 3. Benzylamine and 2-phenylethylamine could also be used in the domino reactions to give the spiro[indoline-3,4’-pyridinones] 3k–3n as the main products (Table 2, entries 19–22). The structures of the prepared spiro compounds 2a–2h and 3a–3n were fully established by

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO₄

• Leandro Lara de Carvalho,
• Robert Alan Burrow and
• Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

• Domingos and co-workers in a PM3 study on domino reactions with nitroalkenes [34]. Additionally, it is possible that the high internal pressure of the solvent acts synergistically to promote the enhancement of the reaction rate of 5a–c and should not be neglected. In all cycloadditions, independent of the

Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes

• Jing Sun,
• Hong Gao,
• Qun Wu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211

• electron-deficient alkynes, such as methyl propiolate or dimethyl acetylenedicarboxylate [27][28][29][30], have shown versatile reactivity and have been widely used as key intermediates in a number of domino reactions to construct heterocyclic systems [31][32][33][34][35][36][37][38][39][40][41][42

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• requires an oxidation by the copper(II) salt to the Pd(II) species, which is then suitable to restart a new catalytic cycle. Recently, the oxidative Pd(II)-catalyzed strategy for the cyclization of alkenylindoles has been extended to the intramolecular domino reactions of indolylallylamides by using the

• /carboxylation reaction. Plausible catalytic cycle for the cyclization/carboxylation of alkenylindoles, adapted from Liu et al. [81]. Intramolecular domino reactions of indolylallylamides through alkenylation/halogenation or alkenylation/esterification processes. Proposed mechanism for the alkenylation

• /esterification process through iminium intermediates. Cyclization of 3-indolylallylcarboxamides involving 1,2-migration of the acyl group from spiro-intermediates. Domino reactions of 2-indolylallylcarboxamides involving N–H functionalization. Cyclization/acyloxylation reaction of 3-alkenylindoles. Doubly

Organocatalytic cascade aza-Michael/hemiacetal reaction between disubstituted hydrazines and α,β-unsaturated aldehydes: Highly diastereo- and enantioselective synthesis of pyrazolidine derivatives

• Zhi-Cong Geng,
• Jian Chen,
• Ning Li,
• Xiao-Fei Huang,
• Yong Zhang,
• Ya-Wen Zhang and
• Xing-Wang Wang

Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195

• heterocyclic compounds have been efficiently generated by means of organocatalytic domino reactions [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69]. In 2009 and 2010, List et al. and the Brière group both reported, separately, the enantioselective synthesis of 2

Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines

• Chittaranjan Bhanja,
• Satyaban Jena,
• Sabita Nayak and
• Seetaram Mohapatra

Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191

• -benzothiopyrans 37 using the closely related catalyst Ia through the same iminium-enamine activation mode of the α,β-unsaturated aldehydes 2. The asymmetric domino reactions proceeded with high yields (53–93%) and with excellent chemo- and stereoselectivities (up to 98% ee) in chloroform as solvent (Scheme 19

Highly enantioselective access to cannabinoid-type tricyles by organocatalytic Diels–Alder reactions

• Stefan Bräse,
• Nicole Volz,
• Franziska Gläser and
• Martin Nieger

Beilstein J. Org. Chem. 2012, 8, 1385–1392, doi:10.3762/bjoc.8.160

• , Germany Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland 10.3762/bjoc.8.160 Abstract After prosperous domino reactions towards benzopyrans, the products were used as the starting material in Lewis acid catalyzed and

Sonogashira–Hagihara reactions of halogenated glycals

• Dennis C. Koester and
• Daniel B. Werz

Beilstein J. Org. Chem. 2012, 8, 675–682, doi:10.3762/bjoc.8.75

• further manipulations on the alkynyl residue. Our previous studies also revealed that even carbohydrate-derived alkynes can be utilized under these reaction conditions in an efficient manner [23]. Our recent interest in domino reactions starting with 2-brominated glycals [26][27][28] motivated us to

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

Gold-catalyzed propargylic substitutions: Scope and synthetic developments

• Olivier Debleds,
• Eric Gayon,
• Emmanuel Vrancken and
• Jean-Marc Campagne

Beilstein J. Org. Chem. 2011, 7, 866–877, doi:10.3762/bjoc.7.99

• domino reactions. Review Gold-catalyzed alcohol substitution Scope and limitations In the past few years, homogeneous gold catalysis has emerged as an efficient tool to activate triple bonds for the addition of various nucleophiles to alkynes. We initially anticipated that, through coordination to π-bond

• might be expected under gold catalysis conditions. For example, it could be interesting to combine both Lewis and π-acidities to promote domino reactions [44][45]. Domino reactions in the presence of bi-nucleophiles We anticipated that by using bi-nucleophiles HNu1–Nu2H, the first nucleophilic

• impressive enantioselective intramolecular direct allylic substitutions using chiral gold(I) complexes [87][88]. We also took advantage of the π- and σ-(Lewis) acidities of gold(III) complexes to promote domino reactions with bi-nucleophiles such as protected hydroxylamines. In the presence of gold(III), the

When gold can do what iodine cannot do: A critical comparison

• Sara Hummel and
• Stefan F. Kirsch

Beilstein J. Org. Chem. 2011, 7, 847–859, doi:10.3762/bjoc.7.97

• scaffolds. Likewise, processes are discussed where mostly identical starting materials are transformed into diverse frameworks depending on whether gold or iodonium activation was used to trigger the reaction. Keywords: catalysis; cycloisomerizations; domino reactions; gold; iodine; Introduction Over the

• past decade, the diverse reactivity of carbophilic Lewis acids has attracted considerable interest in the development of domino reactions [1][2][3][4][5] that are initiated by the catalytic activation of π-systems [6][7][8][9][10][11][12][13]. In particular, the utilization of gold pre-catalysts has

• transformations There are several gold-catalyzed processes for which there are no corresponding iodine counterparts. In general, most of the processes specific for gold are assumed to proceed via gold carbene intermediates. For example, 1,5-enynes 49 can react in gold-catalyzed domino reactions that include a 1,2