Nonbiomimetic total synthesis of indole alkaloids using alkyne-based strategies

Biomimetic natural product synthesis is generally straightforward and efficient because (1) the feasibility of the core synthetic strategy is established in nature, (2) a series of related natural products can be comprehensively synthesised from a common intermediate, (3) the structures of natural products are limited to those suitable for biomimetic strategies and naturally occurring reactions, and (4) starting materials are usually inexpensive. Thus, what is the significance of nonbiomimetic natural product synthesis? We believe that (1) nonbiomimetic synthesis offers more flexibility and can demonstrate the originality of chemists, and (2) the structures of derivatives accessible by nonbiomimetic synthesis may be considerably different from those that are synthesised in nature. This review summarises nonbiomimetic total syntheses of indole alkaloids that are based on constructing the core structures using alkyne reactions.