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

• have been developed recently, including processes using alternative solvents such as ionic liquids and/or scCO2 [56][57][58][59][60][61]. The kinetic resolution of racemic 1-phenylethanol 54 was performed continuously in scCO2, using an immobilized lipase (Candida antarctica, Novozym 435) and vinyl

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• leaching nor the need for catalyst regeneration [22]. Nitroxyl radicals, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), immobilized on silicates [23][24][25][26][27][28][29][30][31][32], fluorous supports [33], soluble and insoluble polymers [22][34][35][36], magnetic nanoparticles [37], and ionic

• liquids [38] have been extensively studied and are useful because the oxidation conditions are mild, selective, and the catalysts do not require regeneration. TEMPO, however, is expensive and difficult to remove from reaction mixtures. For these reasons, TEMPO immobilization is an important goal because

Asymmetric aza-Diels- Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

• Bruce Pégot,
• Olivier Nguyen Van Buu,
• Didier Gori and
• Giang Vo-Thanh

Beilstein J. Org. Chem. 2006, 2, No. 18, doi:10.1186/1860-5397-2-18

• Danishefsky's diene in chiral ionic liquids provides the corresponding cycloadduct with moderate to high diastereoselectivity. The reaction has proved to perform better at room temperature in ionic liquids without either Lewis acid catalyst or organic solvent. Chiral ionic liquids are recycled while their

• , chirality transfer was carried out using chiral Lewis acid catalysts. However, these are often expensive, toxic, and not easily recycled. Up until this point, no chiral solvent is reported to have been used in this transformation. Therefore, when researching chiral ionic liquids (ILs), we had two objectives

• in mind: to promote 'green reaction media' and most importantly to provide a highly efficient chirality transfer due to the high degree of organization of the chiral ionic liquids. Chiral solvents are reported to have been already used as a sole inducer of enantiomeric excess in organic reactions

Study of thioglycosylation in ionic liquids

• Jianguo Zhang and
• Arthur Ragauskas

Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12

• Jianguo Zhang Arthur Ragauskas School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Gerogia, 30332, USA 10.1186/1860-5397-2-12 Abstract A novel, green chemistry, glycosylation strategy was developed based upon the use of ionic liquids. Research studies demonstrated that

• five sequential glycosylation reactions with no impact on product yield. Owing to their unique chemical and physical properties, room temperature ionic liquids (ILs) have received significant attention as alternative solvents for a host of different applications. For example, it has been reported that

• species, as shown in Figure 1. A broader spectrum of anionic counter ions have been reported, including: halides, carbonates, sulfonates, tetrafluorborates, nitrates and chloroaluminates. Changes in the physical properties of ionic liquids, including their melting point, hydrophilicity, lipophilicity and