The C–F bond as a conformational tool in organic and biological chemistry

• Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

• consequently attacks from the bottom (si) face, leading to epoxide 38 with high enantioselectivity. In a control experiment, the related organocatalyst 2-(diphenylmethyl)pyrrolidine (containing a hydrogen atom instead of the fluorine atom of 35) also catalyses the same reaction but with lower

• enantioselectivity suggesting that the fluorine atom of 35 helps to rigidify the activated intermediate and thereby enhances selectivity. Another fluorinated organocatalyst has recently featured in the first example of an asymmetric transannular aldol reaction (Figure 10) [35]. (S)-proline (39) is able to catalyse

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• temperatures than previously reported in batch, resulting in shorter reaction times and lower loadings of the organocatalyst 7 (Scheme 3). Slightly higher yields and selectivities, compared to reactions in both batch and in the microwave were obtained. This study was extended to an example using cyclohexanone

Ru-catalyzed dehydrogenative coupling of carboxylic acids and silanes - a new method for the preparation of silyl ester

• Guo-Bin Liu and
• Hong-Yun Zhao

Beilstein J. Org. Chem. 2008, 4, No. 27, doi:10.3762/bjoc.4.27

• )3Cl [46] and promoted by organocatalyst such as triphenylphosphine [47]. Generally, catalysts such as transition metals are expensive. [CuH(Ph3P)] requires a multiple-step synthetic approach and in-situ generation protocols. Results and Discussion In this communication, we wish to report the first

Towards practical biocatalytic Baeyer- Villiger reactions: applying a thermostable enzyme in the gram- scale synthesis of optically- active lactones in a two-liquid- phase system

• Frank Schulz,
• François Leca,
• Frank Hollmann and
• Manfred T. Reetz

Beilstein J. Org. Chem. 2005, 1, No. 10, doi:10.1186/1860-5397-1-10

• . We compared the system developed in this study to an analogous synthetic organocatalyst for the enantioselective BV-oxidation as described by Murahashi et al. in 2002.[13] The Murahashi system is related to PAMO because it also uses a flavin-derived catalyst within a chiral environment. Of course

• . Comparison of P3-PAMO with Murahashi's chiral bisflavin organocatalyst as a chemical model catalyst for enantioselective BV-oxidations. Supporting Information Supporting Information File 12: Experimental section. Acknowledgements We gratefully acknowledge a gift of the plasmid pADHB1M1-kan encoding 2°ADH