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

• ]. Therefore, synthetic methodologies allowing rapid access to these heterocycles in optically enriched form are highly desirable in organic synthesis and chemical biology/medicinal chemistry. In the past few years very promising progress has been made in this intriguing area, and among the advances

Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• five stereocenters under mild conditions, which was difficult to construct by other synthetic methodologies. Current efforts are in progress to apply this new methodology to synthesize biologically active products. Experimental General procedure for asymmetric [3 + 2] annulation Under an argon

Synthetic glycopeptides and glycoproteins with applications in biological research

• Ulrika Westerlind

Beilstein J. Org. Chem. 2012, 8, 804–818, doi:10.3762/bjoc.8.90

• ) to LecA compared with D-galactose [148]. Similar to the LecB inhibitor FD2, complete inhibition of biofilm formation was observed. Conclusions Recent developments of synthetic methodologies have enabled the preparation of complex glycopeptides and glycoproteins. The availability of structurally

Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method

• Zong-Bo Xie,
• Na Wang,
• Ming-Yu Wu,
• Ting He,
• Zhang-Gao Le and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2012, 8, 534–538, doi:10.3762/bjoc.8.61

• yields by a grinding method under catalyst- and solvent-free conditions. Keywords: catalyst-free; grinding; Michael addition; solvent-free; Introduction Nowadays, chemists are vigorously taking on the challenge of developing green synthetic methodologies to meet the criteria of sustainable

Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

• Michel Chiarucci,
• Mirko Locritani,
• Gianpiero Cera and
• Marco Bandini

Beilstein J. Org. Chem. 2011, 7, 1198–1204, doi:10.3762/bjoc.7.139

• the gold-catalyzed intramolecular allylation of 1.a Supporting Information Supporting Information File 172: Experimental details and characterization of the synthesized compounds. Acknowledgment Acknowledgment is made to Progetto FIRB “Futuro in Ricerca” Innovative sustainable synthetic

• methodologies for C–H activation processes (MIUR, Rome), Università di Bologna.

Triazole–Au(I) complex as chemoselective catalyst in promoting propargyl ester rearrangements

• Dawei Wang,
• Yanwei Zhang,
• Rong Cai and
• Xiaodong Shi

Beilstein J. Org. Chem. 2011, 7, 1014–1020, doi:10.3762/bjoc.7.115

• application of the allene-carbonates and allene-carbamates as building blocks for development of new synthetic methodologies is currently underway in our group. Chemoselective activation of alkyne over allene by the TA–Au catalysts. The counter ligands, an important factor in Au(I) catalysis. The challenge of

Synthesis of novel 5-alkyl/aryl/heteroaryl substituted diethyl 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates by aziridine ring expansion of 2-[(aziridin-1-yl)-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters

• Satish S. More,
• T. Krishna Mohan,
• Y. Sateesh Kumar,
• U. K. Syam Kumar and
• Navin B. Patel

Beilstein J. Org. Chem. 2011, 7, 831–838, doi:10.3762/bjoc.7.95

• use for the development of novel synthetic methodologies and for various organic transformations. Recently, the ring opening of N-vinyl substituted aziridines by selenide nucleophiles to furnish functionalized open chain compounds has been described [23]. N-vinyl substituted aziridines can be

Surfactant catalyzed convenient and greener synthesis of tetrahydrobenzo[a]xanthene-11-ones at ambient temperature

• Pravin V. Shinde,
• Amol H. Kategaonkar,
• Bapurao B. Shingate and
• Murlidhar S. Shingare

Beilstein J. Org. Chem. 2011, 7, 53–58, doi:10.3762/bjoc.7.9

• ]xanthen-11-one using tetradecyltrimethylammonium bromide (TTAB) at room temperature in water is described. Keywords: green chemistry; in-water synthesis; surfactant; tetradecyltrimethylammonium bromide (TTAB); xanthene; Introduction The development of novel synthetic methodologies to facilitate the

Novel tetracyclic structures from the synthesis of thiolactone-isatin hybrids

• Renate Hazel Hans,
• Hong Su and
• Kelly Chibale

Beilstein J. Org. Chem. 2010, 6, No. 78, doi:10.3762/bjoc.6.78

• against the condensing enzymes of type II fatty acid synthesis which operate in a number of pathogenic organisms [6][7][8]. Synthetic methodologies for 1 and a series of racemic and enantiopure thiolactomycin-based analogues have been reported [9][10][11][12][13][14][15][16]. Of particular interest to

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• aminocyclopentitol rings. Trehazolin is a potent trehalase inhibitor in which an aminocyclopentitol ring replaces the glucopyranosyl cation postulated as an intermediate in the enzymatic hydrolysis of α,α-trehalose. Although several synthetic methodologies had successfully been applied to prepare this inhibitor

• synthetic methodologies for thioureido and ureido glycooligomers have made thus enabling the preparation of virtually any oligomeric structure (linear, branched, dendritic and cyclic). The secondary structures adopted by these pseudooligosaccharides have been extensively studied by current NMR and molecular

Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration

• Latif Kelebekli,
• Yunus Kara and
• Murat Celik

Beilstein J. Org. Chem. 2010, 6, No. 15, doi:10.3762/bjoc.6.15

• of carbohydrate mimetics, which can be potent inhibitors of glycosidase (1–4) [11][12][13][14][15][16], we have developed a method for rapid entry to these compounds. Antibiotics containing an aminocyclitol unit have stimulated the development of synthetic methodologies [16] in the search for

A divergent asymmetric approach to aza-spiropyran derivative and (1S,8aR)-1-hydroxyindolizidine

• Jian-Feng Zheng,
• Wen Chen,
• Su-Yu Huang,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2007, 3, No. 41, doi:10.1186/1860-5397-3-41

• of enantiomeric malimide-based synthetic methodologies, [35][36][37][38] we now report concise and highly diastereoselective syntheses of an aza-spiropyran derivative 7 and (1S,8aR)-1-hydroxyindolizidine (ent-3). Results and discussion Previously, we have shown that the addition of Grignard reagents

High stereoselectivity on low temperature Diels- Alder reactions

• Luiz Carlos da Silva Filho,
• Valdemar Lacerda Júnior,
• Mauricio Gomes Constantino,
• Gil Valdo José da Silva and
• Paulo Roberto Invernize

Beilstein J. Org. Chem. 2005, 1, No. 14, doi:10.1186/1860-5397-1-14

• studies [8][9][10][11] that demonstrated how large the influence of the Lewis acid can have on several aspects of the reactions. As part of our research work on synthetic methodologies using niobium pentachloride in a variety of reactions [12][13][14], we have recently started an investigation on