Catalytic nucleophilic 'umpoled' π-allyl reagents

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• The Tsuji-Trost reaction, a cornerstone of palladium-catalyzed allylation, traditionally employs π-allyl intermediates as electrophiles.
• The concept of reversing π-allyl intermediate reactivity (acting as nucleophiles) has been explored since the 1980s.
• Achieving controlled regioselectivity, diastereoselectivity, and enantioselectivity is crucial for complex molecule synthesis.

Purpose of the Study:

• To highlight the concept of 'umpoled' reactivity of π-allyl intermediates.
• To showcase recent advancements in catalytic enantioselective allylation utilizing this reversed reactivity.
• To demonstrate the impact of these methods on natural product and drug synthesis.

Main Methods:

• Utilizing various transition metal sources to facilitate the nucleophilic character of π-allyl intermediates.
• Modifying the electronic environment of metal catalysts through additives and ligands.
• Application of these methodologies in the enantioselective allylation of carbonyl compounds and imines.

Main Results:

• Demonstrated a powerful 'reactivity switch' for π-allyl intermediates, enabling nucleophilic behavior.
• Achieved high levels of regio-, diastereoselectivity, and enantioselectivity in allylation reactions.
• Provided efficient catalytic methods with significant implications for complex molecule synthesis.

Conclusions:

• The 'umpoled' reactivity of π-allyl intermediates offers a versatile strategy in organic synthesis.
• Catalytic enantioselective allylation using nucleophilic π-allyl intermediates is a key enabling technology.
• These advancements significantly impact the efficient construction of natural products and drug candidates.