Low temperature enantiotropic nematic phases from V-shaped, shape-persistent molecules

• Matthias Lehmann and
• Jens Seltmann

Beilstein J. Org. Chem. 2009, 5, No. 73, doi:10.3762/bjoc.5.73

• pyridyl or acceptor substituted aromatic unit at the periphery of the molecule [23][24]. Fluorenone [25], oxadiazole [26], thiazole and thiadiazole [24] derivatives have been synthesised and evidence for biaxiality in their monotropic nematic phases has been presented. Monotropic phases are metastable and

Synthesis and enzymatic evaluation of 2- and 4-aminothiazole- based inhibitors of neuronal nitric oxide synthase

• Graham R. Lawton,
• Haitao Ji,
• Pavel Martásek,
• Linda J. Roman and
• Richard B. Silverman

Beilstein J. Org. Chem. 2009, 5, No. 28, doi:10.3762/bjoc.5.28

• equivalent of acid, which was sufficient to cleave the Boc group. Buffering the reaction resulted in incomplete conversion to the thiazole because acidic conditions are necessary to catalyze the final dehydration step in the reaction [17]. However, the problem was solved by simply neutralizing the mixture on

• does not need to be diprotected to allow the Mitsunobu reaction with phthalimide as the nucleophile to proceed (28a-c). This is presumably because the thiazole nitrogen is less nucleophilic. Cleavage of the phthalimide group gave amines 29a-c. The syntheses of 4a-c were completed by reductive amination

• . Nonetheless, the synthetic methodology is useful for the construction of this ring system. 4-Aminothiazole-based inhibitors with various alkyl groups at the thiazole 5-position could be synthesized, but proved to be unstable in aqueous medium. This is a valuable insight for others contemplating this ring

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• amino sulfide (Rp)-9. Simultaneous sulfide deprotection and thiazole formation was achieved by treating (Rp)-9 with concentrated hydrochloric acid, paraformaldehyde and pyridine [48]. Although the yield of (Rp)-10 is not yet satisfactory, it shows the potential of our methodology for the formation of

• ) 8.89 (1H, s, thiazole CH), 6.81 (1H, d, J = 7.5 Hz, H-13), 6.68 (1H, d, J = 7.5 Hz, H-12), 6.52 (1H, d, J = 8.0 Hz, H-16), 6.46 (1H, d, J = 7.5 Hz, H-15), 6.18 (1H, d, J = 7.5 Hz, H-7), 5.85 (1H, d, J = 7.5 Hz, H-8), 3.99–3.93 (1H, m, H-2 endo), 3.27–3.21 (1H, m, H-1 endo), 3.17–3.11 (1H, m, H-9 endo