A series of crown boronic acids, 1−4, were synthesized and studied as carriers for catecholamine transport through bulk liquid membranes (BLMs) and supported liquid membranes (SLMs). Carrier 1 greatly facilitated the transport of primary catecholamines through BLMs; whereas, the more lipophilic analogues 3 and 4 were less effective. A combination of kinetic, mass spectral, and NMR evidence suggests that the transported species in BLMs is the cyclic, zwitterionic, 1:1 complex 7. The SLM transport studies used a liquid membrane of 2-nitrophenyl octyl ether supported by a thin, flat sheet of porous polypropylene. In the absence of carrier there was neglible dopamine transport (<5 × 10-9 mol/m2·s) at pH 7.2. When the membrane contained carrier 3 (33 mM or about 2% wt), facilitated catecholamine transport was observed in the order of dopamine (5 × 10-7 mol/m2·s) > epinephrine (1.5 × 10-7 mol/m2·s) > norepinephrine (0.8 × 10-7 mol/m2·s). SLMs containing carrier 3 were stable, implying that carrier 3 is a very good candidate for transport mechanism studies. Crown boronic acid 4 was an even better transport carrier of primary catecholamines with a transport order of norepinephrine (4.7 × 10-6 mol/m2·s) > dopamine (3.5 × 10-6 mol/m2·s) ≫ epinephrine (3 × 10-8 mol/m2·s). It is 10 times more effective than an equimolar mixture of boronic acid 5 and crown 6, which is one of best examples of ditopic cooperativity yet observed in SLM transport. SLMs containing 4, however, did not exibit long-term stability. Overall, it is possible that a device based on SLMs containing crown boronic acid carriers can be developed to selectively extract catecholamines from clinical samples.

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The development of a safe, robust process for the preparation of ravuconazole (1), an antifungal agent, is described. The discovery and development of procedures enabling the efficient synthesis of multikilogram quantities of 1 and the process demonstration through plant scale preparations are presented. A controlled means to prepare a Grignard reagent and utilization of Fourier Transform Infrared spectroscopy (FTIR) monitoring to safely conduct the reaction is featured.

The process development and kilogram-scale synthesis of beclabuvir (BMS-791325, 1) is described. The convergent synthesis features the use of asymmetric catalysis to generate a chiral cyclopropane fragment and coupling with an indole fragment via an alkylation. Subsequent palladium-catalyzed intramolecular direct arylation efficiently builds the central seven-membered ring. The target was prepared in 12 linear steps with five isolations in an overall yield of 8%.