Multiple Pd-catalyzed reactions in the synthesis of natural products, drugs, and materials

Abstract

The efficient synthesis of natural products, drugs, and materials with economical and ecological advantages is a very important goal in modern synthetic chemistry. In such an approach, toxic substrates as well as reagents have to be avoided, the amount of waste has to be reduced, and the exploitation of our resources has to be diminished. In this respect, the use of catalytic processes is highly advantageous; however, even more beneficial is the combination of several catalytic processes either in a sequential or, more efficiently, in a domino mode. In this article, the synthesis of several natural products, drugs, and materials is described, employing multiple Pd-catalyzed processes either in a sequential or a domino fashion. Based on a double-Heck reaction developed by us for the preparation of estradiol, the efficient synthesis of the highly potent contraceptive desogestrel is discussed; for the synthesis of α-tocopherol and diversonol an enantioselective domino-Wacker/Heck reaction was utilized, whereas in the case of diversonol, a domino-Wacker/carbonylation was even more effective, and several molecular switches containing a helical tetrasubstituted double bond were prepared employing a domino-carbopalladation/Stille reaction. Finally, acenaphthylenes could be obtained by a domino-carbopalladation/C-H-activation.

In Tandem Auto‐Sustainable Enantioselective Heck‐Matsuda Reactions Directly from Anilines

“…The enantioselective palladium‐catalyzed Heck reaction is a reliable synthetic method to construct new C−C bonds and stereogenic centers in the synthesis of complex molecules [1,2] . In particular, the Heck arylations using aryl (pseudo)halides play an important role in the synthesis of natural products and complex biologically active compounds [3–6] . Although lesser developed, the Heck arylations employing arenediazonium salts – the Heck‐Matsuda (HM) reactions – incorporate several advantages when compared to Heck arylations employing aryl (pseudo)halides, such as higher reactivity, operational simplicity, open‐flask handling, milder, and greener reaction conditions [7–8] .…”

“…[1,2] In particular, the Heck arylations using aryl (pseudo)halides play an important role in the synthesis of natural products and complex biologically active compounds. [3][4][5][6] Although lesser developed, the Heck arylations employing arenediazonium salts -the Heck-Matsuda (HM) reactionsincorporate several advantages when compared to Heck arylations employing aryl (pseudo)halides, such as higher reactivity, operational simplicity, open-flask handling, milder, and greener reaction conditions. [7][8] With a few exceptions, the tetrafluoroborate arenediazonium salts employed in the HM reactions are easily prepared from the readily available anilines and are usually thermostable.…”

Visible Light Catalyzed Step‐Growth Polymerization through Mizoroki–Heck Coupling Reaction

“…Palladium catalyzed Mizoroki–Heck coupling reaction (MHCR) is one of the most powerful and versatile strategies to build CC bonds between aryl halides and olefins 16. It offers the most facile and efficient way to synthesize complex molecules and polymers that are important in applications such as conjugated photoelectronic materials,17 pharmaceutical18 and agrochemical industries 19. In the past few decades, MHCR was promoted by several new methods such as physical (involving microwaves, ultrasound, and high‐pressure) and physicochemical (micellar solutions and electrochemistry) activation techniques in lieu of traditional thermal activation 20.…”

Cross‐Coupling of Organyl Halides with Alkenes – The Heck Reaction

“…The ring closure of the eight-membered ring to complete the rigid and compact tricyclic system is not trivial [145]. The application of a metal such as palladium probably brings in a certain template effect by precoordination (Figure 8.7 and Figure 8.8) [422].…”