Zeolite catalyzed solvent- free one-pot synthesis of dihydropyrimidin- 2(1H)-ones – A practical synthesis of monastrol

• Mukund G. Kulkarni,
• Sanjay W. Chavhan,
• Mahadev P. Shinde,
• Dnyaneshwar D. Gaikwad,
• Ajit S. Borhade,
• Attrimuni P. Dhondge,
• Yunnus B. Shaikh,
• Vijay B. Ningdale,
• Mayur P. Desai and
• Deekshaputra R. Birhade

Beilstein J. Org. Chem. 2009, 5, No. 4, doi:10.3762/bjoc.5.4

• ) have recently gained tremendous importance in organic and medicinal chemistry. The main contributing factors are the high atom economy, wide application in combinatorial chemistry and diversity-oriented synthesis [4][5][6][7][8][9][10]. In general, the dihydropyrimidones (DHPMs) are known for their

Catalytic synthesis of (E)-α,β-unsaturated esters from aldehydes and 1,1-diethoxyethylene

• Rubén Manzano,
• Lidia Ozores,
• Andreas Job,
• Lars Rodefeld and
• Benjamin List

Beilstein J. Org. Chem. 2009, 5, No. 3, doi:10.3762/bjoc.5.3

• variants are widely used [1]. A general problem with these approaches, however, is their unsatisfactory atom economy resulting in significant by-product formation (Scheme 1, eq 1–2). Alternatives have been suggested but a solution that is both as general and efficient as the Wittig procedures and

• satisfactory with respect to the demand for atom economy is still needed [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. We have recently developed a new approach based on the Knoevenagel condensation of readily available and inexpensive malonate half esters with aldehydes which

One-pot preparation of substituted pyrroles from α-diazocarbonyl compounds

• Fernando de C. da Silva,
• Mauricio G. Fonseca,
• Renata de S. Rianelli,
• Anna C. Cunha,
• Maria C. B. V. de Souza and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2008, 4, No. 45, doi:10.3762/bjoc.4.45

• yield, with high atom economy, and be more convergent than one or two-component reactions. α-Diazocarbonyl compounds have a long history of useful applications in organic chemistry. They are easily prepared from readily accessible precursors and can be used in a wide variety of chemical transformations

EcoScale, a semi- quantitative tool to select an organic preparation based on economical and ecological parameters

• Koen Van Aken,
• Lucjan Strekowski and
• Luc Patiny

Beilstein J. Org. Chem. 2006, 2, No. 3, doi:10.1186/1860-5397-2-3

• alternative. [1][2] The main parameters and approaches are briefly discussed as follows. Atom economy [3][4] This parameter is the ratio of the molecular weight of the target molecule to the sum total of the molecular weights of all the substances produced in the stoichiometric equation for the reaction

• involved. It takes into account the amount of the reagents incorporated into the end product. Cycloadditions are examples of transformations with 100% atom economy. For other reactions (e.g. substitution reaction), a 100 % economy can never be reached due to the intrinsic nature of the reaction. The main

• use of this parameter is to adapt reaction sequences in a way that transformations with low atom economy are limited to a minimum. Environmental factor (E-factor) [5][6][7][8] This factor is the ratio of the weight of generated waste to the total weight of the end product. It is a useful tool for