We describe herein a highly diastereo‐ and enantioselective [4+3]‐cycloannulation of ortho‐quinone methides and carbonyl ylides to furnish functionalized oxa‐bridged dibenzooxacines with excellent yields and stereoselectivity in a single synthetic step. The combination of rhodium and chiral phosphoric acid catalysis working in concert to generate both transient intermediates in situ provides direct access to complex bicyclic products with two quaternary and one tertiary stereogenic centers. The products may be further functionalized into valuable and enantiomerically highly enriched building blocks.

A stereoselective (3 + 3)-cycloannulation of in situ generated carbonyl ylides with indolyl-2-methides has been developed furnishing oxa-bridged azepino­[1,2-a]­indoles within one synthetic step. This process is enabled by cooperative rhodium and chiral phosphoric acid catalysis to produce both transient intermediates in separate catalytic cycles. The products comprising three stereogenic centers were obtained with good stereoselectivity and yields and display valuable heterocyclic complexity.

We report the first enantioselective allenylation of Pd enolates enabled by cooperative Pd/Brønsted acid catalysis employing β-keto esters and propargyl alcohols. The enantioselectivity originates solely from an in-situ-generated chiral metal enolate in an open transition state with no additional binding of the propargyl component to the catalyst. Thus a broad substrate scope was established, furnishing hitherto inaccessible products in very good yields with excellent enantioselectivities (up to >99:1 e.r.).

Im Rahmen dieser Arbeit wurde ein Verfahren zur diastereo‐ und enantioselektiven [4+3]‐Cycloanellierung von ortho‐Chinonmethiden und Carbonylyliden entwickelt, das funktionalisierte, sauerstoffverbrückte Dibenzooxazine in exzellenten Ausbeuten und Stereoselektivitäten innerhalb eines einzelnen Syntheseschrittes zugänglich macht. Die kooperative Katalyse von Rhodium und einer chiralen Brønsted‐Säure ermöglicht die in situ Erzeugung zweier hochreaktiver Intermediate, die zu komplexen, bicyclischen Produkten mit einem tertiären und zwei quartären Stereozentren reagieren. Diese wurden durch weitere Transformationen in wertvolle, enantiomerenangereicherte Synthesebausteine überführt.