Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• using two Teledyne Isco D-series dual syringe pumps (100 DX, with Hastelloy™ syringes) and were continuously mixed in a T-piece. After mixing, the combined starting material solution was fed into a Chemtrix Plantrix® MR260 [27] plate-type flow reactor. This plate flow reactor configuration consisted of

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• consisted of two syringe pumps, which pump the reactants – a nitrating mixture and benzaldehyde – through 20 mL glass syringes connected to SS316 tubes by a glass-to-metal PTFE connector. After the micromixer a hastelloy tube (1.38 mm i.d. and 6 m long) acted as a residence time unit immersed in a

• conversion rate but lower selectivity for the desired product. Contrary to a patent description [45], glass is less suited than metal SS316 or Hastelloy due to lower thermal conductivity. Thus, the choice of material of the reactor plays a significant role in controlling the yield and selectivity of the

Koch–Haaf reaction of adamantanols in an acid-tolerant hastelloy-made microreactor

• Takahide Fukuyama,
• Yu Mukai and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2011, 7, 1288–1293, doi:10.3762/bjoc.7.149

• combining an acid-tolerant hastelloy-made micromixer, a PTFE tube, and a hastelloy-made microextraction unit, a packaged reaction-to-workup system was developed. By means of the present system, the multigram scale synthesis of 1-adamantanecarboxylic acid was achieved in ca. one hour operation. Keywords

• : continuous flow system; hastelloy; Koch–Haaf reaction; microreactor; Introduction The recent evolution of microreactor technology has allowed synthetic chemists to use this precisely sophisticated reaction apparatus in place of the well-established glassware batch flask [1][2][3][4][5][6][7][8][9][10

• causes a serious problem especially for large scale synthesis. Herein, we report that the Koch–Haaf reaction in a microflow reactor can be carried out at room temperature without any cooling equipment. The employed hastelloy-made microreactor system was compatible with corrosive (strongly acidic

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

• Bernhard Gutmann,
• Toma N. Glasnov,
• Tahseen Razzaq,
• Walter Goessler,
• Dominique M. Roberge and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

• heated flow devices with either stainless steel or Hastelloy coils in the same temperature region. In contrast, in a flow instrument that utilizes direct electric resistance heating of the reactor coil, tetrazole decomposition was dramatically accelerated with rate constants increased by two orders of

• same reaction was subsequently carried out in flow devices using metal coils made from different materials heated either in an oil bath or with an Al heating block. Remarkably, the stability of tetrazole 2 in a 5.21 mL Hastelloy C-4 coil (i.d. 2.0 mm) at 240 °C was very close to the stability observed

• in the microwave batch experiment (Figure S8, Supporting Information File 1). The superior resistance of the Hastelloy material toward the NMP/AcOH/H2O mixture at high temperature was also evident from an ICPMS analysis of the solvent mixture processed in the Hastelloy C-4 capillary at 220 °C (5 min

Continuous flow based catch and release protocol for the synthesis of α-ketoesters

• Alessandro Palmieri,
• Steven V. Ley,
• Anastasios Polyzos,
• Mark Ladlow and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2009, 5, No. 23, doi:10.3762/bjoc.5.23

• (unpacked). The coil reactors are made from a selection of materials including PTFE, PEEK, stainless steel or Hastelloy® and accommodate volumes from 2–20 mL. The column reactor (Figure 1, A) can be heated up to 150 °C and the coil heater (Figure 1, B) up to 260 °C, over a range of flow rates between 0.01