Catalytic Stereoselective Multicomponent Reactions for the Synthesis of Spiro Derivatives: Recent Progress

Abstract

Spiro derivatives are important scaffolding substances found in many natural products and pharmaceuticals. In the last decade, numerous new approaches based on multicomponent reactions have been explored for the selective and efficient development of new spiro derivatives using various organocatalytic and transition metal‐based catalytic systems. This Review discusses pioneering advances in the field of catalytic stereoselective multicomponent reactions for the preparation of various spiro derivatives. These include stereoselective Michael cascade cyclization reactions, cycloadditions, diastereoselective reactions, and miscellaneous reactions for the synthesis of spiro‐hetero/carbocycles. Advances in the last decade have made it possible to synthesize various spiro compounds with good to excellent stereoselectivity under appropriate reaction conditions. However, achieving high regioselectivity in several described multicomponent reactions remains a challenge. Organocatalysts and transition‐metal‐based catalysts play a crucial role in achieving this milestone. Proposed catalytic mechanisms and supporting evidence are highlighted in this Review. The progress described in catalytic stereoselective approaches for spiro derivatives is immense. However, it is expected that new stereoselective synthetic methods will soon be developed that can be widely used for the preparation of spiro‐heterocycles/carbocycles.

An efficient, catalyst-free and aqueous ethanol-mediated synthesis of 5-((2-aminothiazol-5-yl)(phenyl)methyl)-6-hydroxypyrimidine-2,4(1H,3H)-dione derivatives and their antioxidant activity

“…20 It has driven the synthetic community to look for better ecologically friendly syntheses and reactions to speed up preparation and use less energy and effort. 21–23…”

Dehydroabietane-type bifunctional organocatalysts in asymmetric synthesis: recent progress

“…Owing to their specic strong hydrogen-bonding capabilities combined with the notable features of the dehydroabietane scaffold, a series of effective bifunctional organocatalysts based on the dehydroabietane structure have been employed in various catalytic asymmetric reactions so far. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The dehydroabietane-type bifunctional organocatalysts can be broadly classied into two categories according to their hydrogen-bonding donor structures: thioureas (C1a-C8, including immobilized thioureas) and squaramides (C9-C11) as illustrated in Fig. 2.…”

“…1), have been extensively utilized as chiral building blocks for the synthesis of numerous natural and synthetic molecules with diverse chemical catalytic or biological activities that find wide applications in pharmaceuticals, medicine, asymmetric synthetic chemistry, and various other fields. 3–26 As depicted in Fig. 1, AA is a monocarboxylic acid diterpene possessing a unique chiral tricyclic rigid framework with two conjugated double bonds.…”

“…Chiral thioureas and squaramides are representative organocatalysts in asymmetric synthesis that have been developed for enantioselective reactions. 11–34 Owing to their specific strong hydrogen-bonding capabilities combined with the notable features of the dehydroabietane scaffold, a series of effective bifunctional organocatalysts based on the dehydroabietane structure have been employed in various catalytic asymmetric reactions so far. 11–26…”

“…11–34 Owing to their specific strong hydrogen-bonding capabilities combined with the notable features of the dehydroabietane scaffold, a series of effective bifunctional organocatalysts based on the dehydroabietane structure have been employed in various catalytic asymmetric reactions so far. 11–26…”