Dong J, Ostertag A, Sparr C. o-Quinodimethane Atropisomers: Enantioselective Synthesis and Stereospecific Transformation.
Angew Chem Int Ed Engl 2022;
61:e202212627. [PMID:
36256547 PMCID:
PMC10100317 DOI:
10.1002/anie.202212627]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Indexed: 11/07/2022]
Abstract
o-Quinodimethanes have remarkable utility as reactive intermediates in Diels-Alder reactions, enabling significantly accelerated routes to complex polycyclic compounds. The discovery of different discrete precursors to thermally generate o-quinodimethanes thereby greatly augmented their availability and versatility. However, due to the required high temperatures and the immense reactivity of o-quinodimethanes, stereoselectivity to afford isomerically defined products still constitutes a critical challenge. Herein, we describe the accessibility of atropisomeric o-quinodimethanes, the enantioselective synthesis of their precursors, their remarkable configurational stability and the stereospecific transformation by the benzannulation of dienophiles. A catalyst-stereocontrolled [2+2+2] cycloaddition, the generation of o-quinodimethane atropisomers and ensuing stereospecific Diels-Alder reactions enabled enantioselectivities through these transient intermediates with of up to 96 : 4 e.r.
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