Flow Giese reaction using cyanoborohydride as a radical mediator

Fukuyama, Takahide; Kawamoto, Takuji; Kobayashi, Mikako; Ryu, Ilhyong

doi:10.3762/bjoc.9.208

Cited by 18 publications

(4 citation statements)

References 27 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In pursuit of a potential substitute for tin hydride, we envisioned that radical methodologies based on borohydride as the hydrogen donor would have great potential and would be quite useful. In our preliminary communication, we reported that the reductive addition of alkyl radicals to electron-deficient olefins , and the related carbonylation reactions proceeded in the presence of cyanoborohydride reagents as radical mediators (Scheme ). We also reported the radical hydroxymethylation of alkyl iodides with CO or HCHO .…”

Section: Introductionmentioning

confidence: 99%

Borohydride-Mediated Radical Addition Reactions of Organic Iodides to Electron-Deficient Alkenes

et al. 2014

Self Cite

View full text Add to dashboard Cite

Cyanoborohydrides are efficient reagents in the reductive addition reactions of alkyl iodides and electron-deficient olefins. In contrast to using tin reagents, the reaction took place chemoselectively at the carbon-iodine bond but not at the carbon-bromine or carbon-chlorine bond. The reaction system was successfully applied to three-component reactions, including radical carbonylation. The rate constant for the hydrogen abstraction of a primary alkyl radical from tetrabutylammonium cyanoborohydride was estimated to be <1 × 10(4) M(-1) s(-1) at 25 °C by a kinetic competition method. This value is 3 orders of magnitude smaller than that of tributyltin hydride.

show abstract

Section: Introductionmentioning

confidence: 99%

Borohydride-Mediated Radical Addition Reactions of Organic Iodides to Electron-Deficient Alkenes

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…More recently, Zheng and Guo reported that TMEDA-catalyzed radical arylation of benzene under photoirradiation conditions with high tolerance of functional groups . Recently, we reported radical C–C bond-forming reactions using borohydride reagents as chain mediators. , In this paper, we report that cyanoborohydride promotes the synthesis of biaryl compounds from iodoarenes and benzene under aerobic photoirradiation conditions. This reaction proceeds in a chemoselective fashion for bromo- and iodo- substituted arenes.…”

mentioning

confidence: 72%

Cyanoborohydride-Promoted Radical Arylation of Benzene

2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…The flow reaction system has been recognized as a useful platform for organic chemistry as well as pharmaceutical, chemical industries . These flow reaction systems with high ratio of surface area to volume have unique features, such as efficient transfers of heat and mass, enabling diverse green and sustainable chemical processes . The precise control of reaction time is one of the most outstanding advantage of the flow‐synthetic methods.…”

Section: Comparative Performance Of Anionic Fries Rearrangement Reactmentioning

confidence: 99%

Enhanced Controllability of Fries Rearrangements Using High‐Resolution 3D‐Printed Metal Microreactor with Circular Channel

Lee

Roberts

et al. 2019

Small

View full text Add to dashboard Cite

ratio of surface area to volume have unique features, such as efficient transfers of heat and mass, enabling diverse green and sustainable chemical processes. [3,4] The precise control of reaction time is one of the most outstanding advantage of the flow-synthetic methods. Highly reactive chemicals that are impossible to handle in conventional batch reactors can be controlled by the precise adjustment of retention time in a flow reactor. [5] In particular, it is highly striking to control the ultrafast chemistry associated with highly short-lived unstable intermediates at high flow rates that can maximize the mixing efficiency at short time in the confined microreaction space. [6] Moreover, the high flow rates may facilitate a high throughput production for industrial applications, which would overcome a longstanding limitation in low productivity of conventional microfluidics. [7] Recently, we reported the control of extremely ultrafast reactions, rapid intramolecular rearrangement via the newly devised microreactor with a small internal volume. [8] The polyimide (PI) film layered microfluidic device with high durability to chemicals and pressure demonstrated outpacing the intramolecular rearrangement reaction by controlling within submillisecond. [8a] However, the use of metal device is much more desirable rather than the polymer material for the temperature control of highly sensitive intermediates as well as the durability of device. Furthermore, the laser ablation technique to fabricate the channel structure in PI film is limited to constructing only rectangular cross-sectional channel that the edges of cross section cause a decrease of mixing efficiency. Thus, the complex mixing structure is required to increase the mixing efficiency in case of PI film-based devices. In order to carry out the ultrafast chemistry in a more effective manner, the new conceptual microreactor is still demanding to enhance the mixing efficiency in smaller reaction volume of the simpler design for facile manufacturing. Therefore, an advanced approach is very desirable to fabricate the well-designed microreactor with high-resolution geometry.3D printing techniques have widely been developed for applications in various academic and industrial fields. The additive manufacturing technology is also inevitably penetrating to the field of microfluidic device fabrication, because it enables a facile, one-step manufacture of monolithic flow reactors by High-resolution 3D-printed stainless steel metal microreactors (3D-PMRs) with different cross-sectional geometry are fabricated to control ultrafast intramolecular rearrangement reactions in a comparative manner. The 3D-PMR with circular channel demonstrates the improved controllability in rapid Fries-type rearrangement reactions, because of the superior mixing efficiency to rectangular cross-section channels (250 µm × 125 µm) which is confirmed based on the computational flow dynamics simulation. Even in case of very rapid intramolecular rearrangement of sterically small acetyl group ...

show abstract

Flow Giese reaction using cyanoborohydride as a radical mediator

Cited by 18 publications

References 27 publications

Borohydride-Mediated Radical Addition Reactions of Organic Iodides to Electron-Deficient Alkenes

Borohydride-Mediated Radical Addition Reactions of Organic Iodides to Electron-Deficient Alkenes

Cyanoborohydride-Promoted Radical Arylation of Benzene

Enhanced Controllability of Fries Rearrangements Using High‐Resolution 3D‐Printed Metal Microreactor with Circular Channel

Contact Info

Product

Resources

About