1,3‐Difunctionalizations of [1.1.1]Propellane via 1,2‐Metallate Rearrangements of Boronate Complexes

• Published in: Angewandte Chemie Vol. 132; no. 10; pp. 3945 - 3949
• Main Authors: Yu, Songjie, Jing, Changcheng, Noble, Adam, Aggarwal, Varinder K.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 02.03.2020
• Subjects: [1.1.1]Propellan; Aromatic compounds; Bicyclo[1.1.1]pentane; Borylierung; Chemistry; Esters; Intermediates; Mehrkomponentenreaktionen; Organic chemistry; Pentanes; Reagents; Zweifel-Olefinierung
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201914875

1,3‐Disubstituted bicyclo[1.1.1]pentanes (BCPs) are valuable bioisosteres of para‐substituted aromatic rings. The most direct route to these structures is via multicomponent ring‐opening reactions of [1.1.1]propellane. However, challenges associated with these transformations mean that difunctionalized BCPs are more commonly prepared by multistep reaction sequences with BCP‐halide intermediates. Herein, we report three‐ and four‐component 1,3‐difunctionalizations of [1.1.1]propellane with organometallic reagents, organoboronic esters, and a variety of electrophiles. This process is achieved by trapping intermediate BCP‐metal species with boronic esters to form boronate complexes, which are versatile intermediates whose electrophile‐induced 1,2‐metallate rearrangement chemistry enables a broad range of C−C bond‐forming reactions. Die modulare Synthese von 1,3‐difunktionalisierten Bicyclo[1.1.1]pentanen (BCPs) wurde durch Mehrkomponenten‐Kupplungen zwischen metallorganischen Reagenzien, [1.1.1]Propellan und Organobor‐Estern erreicht. Durch die Nutzung der vielseitigen 1,2‐Metallat‐Umlagerung der in situ erzeugten Boronatkomplexe konnte eine Reihe von C‐C‐Bindungsbildungsreaktionen ohne die Notwendigkeit einer Übergangsmetallkatalyse durchgeführt werden.