Alkylation of acylmetalates with alkyl halides to prepare Fischer carbene complexes: an improved protocol

Visible-Light-Induced In Situ Generation of Fischer-Type Copper Carbene Complexes from Acylsilanes and Its Application to Catalytic [4 + 1] Cycloaddition with Siloxydienes

“…However, by using 13 C-enriched 1a (20% enriched at carbonyl carbon), a characteristic signal at δ = 304 ppm was clearly observed in the 13 C NMR spectrum, which strongly suggested the newly formed species 2 was a desired siloxycarbene–copper complex (Figure ). , The UV–vis spectra also indicated that the structure of 2 is a Cu–carbene complex; the n−π* absorption (ca. 420 nm) of 1a disappeared upon photoirradiation (420 nm) to a mixture of 1a and [Cu­(CH 3 CN) 4 ]­PF 6 , and a new absorption was observed at 444 nm, which was in agreement with the results of the TDDFT calculation (ca.…”

The Mechanism of Phosphonium Ylide Alcoholysis and Hydrolysis: Concerted Addition of the O−H Bond Across the P=C Bond

“…Examination of the 1 H NMR spectrum of the crude hydrolysis product formed from the reaction of 25 and (−)‐menthol shows that the alcohol product is (−)‐menthol ( δ H =3.3 ppm). This shows that the addition of water to the ylide/phosphorane mixture results in the hydrolysis of the ylide exclusively, whereas if the phosphorane ( 24 ) were hydrolysed, one would expect to see evidence of the formation of (+)‐neomenthol ( δ H =4.10 ppm in CDCl 3 ) or 2‐menthene ( δ H =5.52 ppm in CDCl 3 ; see Scheme ) . The starting alcohol is also the only observed non‐phosphorus‐containing product when water is added to reactions involving 19 , 22 and 23 (demonstrated by NMR spectroscopy and, in the case of 23 , GC), which we again interpret to be a consequence of hydrolysis of the starting ylide…”

Joint Isotherm Calorimetric Titration–DFT Investigation of the Demethoxy-Amination of Fischer Carbenes

“…All Fischer carbenes (2a-c) [84][85][86][87] were synthesized following literature procedures [1,85,[88][89][90] (Scheme 2). The analysis of both the starting methoxycarbene complexes and the isolable aminocarbene complexes by 1 H and 13 C NMR and IR spectroscopies perfectly matched with the analytical data reported in the literature.…”