Crystalline BP‐Doped Phenanthryne via Photolysis of The Elusive Boraphosphaketene. Issue 10 (29th January 2020)

• Record Type: Journal Article
• Authors: Yang, Wenlong; Krantz, Kelsie E.; Dickie, Diane A.; Molino, Andrew; Wilson, David J. D.; Gilliard, Robert J.
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 10(2020)
• Page Start: 3971
• Page End: 3975
• Publication Date: 2020-01-29
• Subjects: boron -- carbenes -- heterocycles -- phenanthryne -- phosphorus; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201916362
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The synthesis and reactivity study of the first isolable boraphosphaketene, cyclic(alkyl)(amino) carbene (CAAC)‐borafluorene‐P=C=O (2 ), is described. Photolysis of compound 2 results in the formation of CAAC‐stabilized BP‐doped phenanthryne (3 ) through tandem decarbonylation, monoatomic phosphide insertion, and ring‐expansion. Notably, while BN‐doped phenanthryne was previously discussed as a reactive intermediate which could not be isolated, the heavier BP‐doped analogue exhibits remarkable solution and solid‐state stability. The reactivity of 2 with stable carbenes was also explored. Addition of CAAC to 2 led to migration of the original CAAC ligand from boron to phosphorus and coordination of the added CAAC to carbon, affording compound 4 . Reaction of 1, 3‐diisopropyl‐4, 5‐dimethylimidazol‐2‐ylidene (NHC) with 2 resulted in N−C bond activation to give the unusual spiro‐heterocyclic compound (5 ). Abstract : P brings stability : The first BP‐doped phenanthryne has been synthesized via photolysis of the elusive boraphosphaketene. While BN‐doped phenanthryne was previously discussed as a reactive intermediate that could not be isolated, the heavier BP‐doped analogue exhibits remarkable solution and solid‐state stability.