Synthesis of 2-amino-3-arylpropan-1-ols and 1-(2,3-diaminopropyl)-1,2,3-triazoles and evaluation of their antimalarial activity

• Matthias D’hooghe,
• Stéphanie Vandekerckhove,
• Karen Mollet,
• Karel Vervisch,
• Stijn Dekeukeleire,
• Liesbeth Lehoucq,
• Carmen Lategan,
• Peter J. Smith,
• Kelly Chibale and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2011, 7, 1745–1752, doi:10.3762/bjoc.7.205

• emergence of multiple drug resistance to clinically established antimalarial drugs, however, there is a compelling need to introduce new chemicals that can overcome this resistance. In 2007, nitrogen-analogues of glycerol, which have a long-standing tradition in medicine as β-blockers, were introduced as a

Coupled chemo(enzymatic) reactions in continuous flow

• Ruslan Yuryev,
• Simon Strompen and
• Andreas Liese

Beilstein J. Org. Chem. 2011, 7, 1449–1467, doi:10.3762/bjoc.7.169

• ]. From a formal point of view, reactions such as the lipase-catalyzed hydrolysis of triglycerides to glycerol and fatty acids, or amylase-catalyzed hydrolysis of amylose to glucose should also be classified as multistep-reaction processes, because they proceed stepwise via a sequence of intermediates

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• on DNA cleavage In order to get further insight into the mechanism of the DNA cleavage by the three conjugates, we used the plasmid relaxation assays for the cleavage with conjugates 1, 6, and 7 in the presence of hydroxyl radicals (glycerol, DMSO) and singlet oxygen (NaN3) scavengers [65]. The

• hydroxyl radical scavengers, glycerol and DMSO, protected DNA from the cleavage by 33 and 26%, respectively, whereas NaN3 showed ~43% protection. The large protecting effect of NaN3, the singlet oxygen scavenger, is consistent with the efficient photoaddition reaction of its chromophore via triplet

• (Figure 8c). Only glycerol at pH 6 and glycerol and DMSO at pH 8 showed ~10% of protection. Little effect was observed for NaN3, suggesting that the formation of singlet oxygen via triplet energy transfer is inefficient, possibly because of a short triplet lifetime and fast intramolecular photocyclization

About the activity and selectivity of less well-known metathesis catalysts during ADMET polymerizations

• Hatice Mutlu,
• Lucas Montero de Espinosa,
• Oĝuz Türünç and
• Michael A. R. Meier

Beilstein J. Org. Chem. 2010, 6, 1149–1158, doi:10.3762/bjoc.6.131

• first time on the performance of two well-defined, stable Ru–indenylidene catalysts C1 and C2, and the “boomerang complex” C3 (Figure 2) during ADMET polymerizations. The ADMET monomer was synthesized by a procedure adapted from the literature using 1,3-propanediol, which can be prepared from glycerol

Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length

• Florian K. Wolf,
• Anna M. Fischer and
• Holger Frey

Beilstein J. Org. Chem. 2010, 6, No. 67, doi:10.3762/bjoc.6.67

• contrast to dendrimers, where functional groups are exclusively located at the surface, poly(glycerol) scaffolds also contain hydroxy groups throughout the structure. At first glance this might be considered a disadvantage, however, this is in fact beneficial for the significantly hydrophilized core

• crystallization tendencies of the polymer. Results and Discussion The hyperbranched poly(glycerol)s (PGs) with multiple poly(glycolide) arms were prepared by a straightforward two-step approach as shown in Figure 1. In the first step, we polymerized glycidol anionically by the method described previously [19

• secondary hydroxy groups of the polymer n(OH) is equal to the sum of the initiator functionality f and the degree of polymerization DPn. By varying of the initiator/monomer ratio, two hyperbranched poly(glycerol) samples with different degrees of polymerization DPn were obtained. Their theoretical number of

N-acylation of ethanolamine using lipase: a chemoselective catalyst

• Mazaahir Kidwai,
• Roona Poddar and
• Poonam Mothsra

Beilstein J. Org. Chem. 2009, 5, No. 10, doi:10.3762/bjoc.5.10

• (triacyl glycerol hydrolases EC 3.1.1.3) catalyze hydrolysis, esterification, transesterification, thioesterification, amidation, epoxidation etc. [5][6][7][8][9][10]. The use of immobilized lipases is on the rise, as these work well with non-aqueous media [11]. Apart from the convenient handling, these

Synthesis of new C^α-tetrasubstituted α-amino acids

• Andreas A. Grauer and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 5, doi:10.3762/bjoc.5.5

• , 0.9 C, trans-COO). IR (neat) [cm−1]: = 2977, 2877, 2361, 1708, 1492, 1392, 1366, 1250, 1157, 1085, 1052, 940, 848. CI-MS (NH3): m/z 218.2 (9) [MH+ − 2 C4H8], 274.2 (51) [MH+ − C4H8], 330.2 (100) [MH+]. HR-MS (FAB, MeOH/glycerol) [MH+] calcd. for C17H32NO5 330.2280; found 330.2288. MF C17H31NO5. MW

• C, trans-COO). IR (neat) [cm−1]: = 3326, 2957, 2359, 1708, 1497, 1366, 1250,1160, 1116, 1098, 1055, 885, 849, 781. CI-MS (NH3): m/z (%) = 244.2 (25) [MH+ − Boc], 288.2 (44) [MH+ − C4H8], 305.2 (19) [MNH4+ − C4H8], 344.3 (100) [MH+]. HR-MS (FAB, MeOH/glycerol): [M+] calcd. for C18H33NO5 343.2359

• ); 170.7 (Cquat, 0.25 C, cis-COO). IR (neat) [cm−1]: = 3334, 2975, 2357, 1709, 1490, 1366, 1250, 1157, 1077, 949, 848. CI-MS (NH3): m/z (%) = 230.2 (18) [MH+ − Boc], 274.2 (30) [MH+ − C4H8], 291.2 (19) [MNH4+ − C4H8], 330.2 (100) [MH+], 676.6 (9) [2 M + NH4+]. HR-MS (FAB, MeOH/glycerol): [M+] calcd. for