Bhisma K. Patel

By Bhisma K. Patel and Amitava Rakshit

In last few decades, the transition metal-catalyzed C-H bond activation and alkyne annulation reactions have turned out to be effective methods for the construction of highly important heterocycles. In particular, the Ru(II) catalysts have been used for the oxidative coupling between an internal alkynes and readily available nitrogen directed compounds in a rapid and sustainable manner. The Ru(II) catalysts are very much beneficial due to their stability in both air and water, ease of preparation, inexpensive than those of Rh(III) and designer Co(III) catalysts usually used for alkyne annulation reactions, requirement of mild reaction conditions, and compatible with various oxidants. Owing to these advantages of Ru(II) catalysts herein, we attempt to highlight the recent development in C-H activation and annulation reactions, which lead to the formation of several important N-heterocycles.

Part of the book: Ruthenium

By Bhisma K. Patel, Tipu Alam and Amitava Rakshit

In the last few years, the photo-redox process via single-electron transfer (SET) has received substantial attention for the synthesis of targeted organic compounds due to its environmental friendliness and sustainability. Of late visible-light-mediated difunctionalization of alkenes has gained much attention because of its step economy, which allows the consecutive installation of two functional groups across the C=C bond in a single operation. The construction of N-containing compounds has always been important in organic synthesis. Molecules containing C-N bonds are found in many building blocks and are important precursors to other functional groups. Meanwhile, C-N bond formation via the addition of the C=C double bond is gaining prominence. Therefore, considering the influence and synthetic potential of the C-N bond, here we provide a summary of the state of the art on visible-light-driven difunctionalizations of alkene. We hope that the construction of the C-N bond via visible-light-mediated difunctionalization of alkenes will be useful for medicinal and synthetic organic chemists and will inspire further reaction development in this interesting area.

Part of the book: Alkenes

By Suresh Rajamanickam and Bhisma K. Patel

Thermally activated delayed fluorescent (TADF) molecules undergo efficient intersystem crossing (ISC) and reverse intersystem crossing (RISC) processes, making them as third-generation emitters in organic light-emitting diodes (OLEDs), photodynamic therapy (PDT) and time-resolved luminescence imaging. Apart from these applications, recently, TADF molecules have been used extensively as photocatalysts in light-mediated synthesis. In general, highly expensive complexes of Rh, Ir, Ru and organic dyes (Eosin Y, Rose Bengal, 9-mesityl-10-methylacridinium perchlorate [Acr-Mes]+ClO4−) are commonly used in the photocatalysis process. Organic-TADF based molecules help to avoid these costly metal catalysts and frequently used organic dyes, making the reaction economical and greener. This chapter will briefly summarize the photocatalytic properties of organic-TADF compounds in organic synthesis.

Part of the book: Green Chemistry