Catalytic asymmetric C–H insertion reactions of α-diazocarbonyl compounds

Enantioselective copper catalysed intramolecular C–H insertion reactions of α-diazo-β-keto sulfones, α-diazo-β-keto phosphine oxides and 2-diazo-1,3-diketones; the influence of the carbene substituent

“…23 Since this pioneering work, insertion reactions have been further developed to achieve high levels of enantiocontrol with a diverse range of chiral rhodium catalysts. 1,2 Previous studies from our laboratory have shown that the use of a copper catalyst system comprised of copper-bis(oxazoline)-NaBARF is very effective in inducing high levels of enantiocontrol in C-H insertions of α-diazocarbonyl compounds bearing arylsulfonyl substituents. Thiopyrans 1, cyclopentanones 2 and γ-lactams 3 have been synthesised in excellent enantioselectivities of up to 98 %ee, 22 89 %ee 24 and 78 %ee 25 respectively (Scheme 2).…”

“…22,25 The enantioselectivities described above are the highest reported for copper catalysed C-H insertion reactions 29 and, indeed, are comparable with the enantioselectivities reported for the rhodium mediated C-H insertions. 2 Our studies into enantioselective intramolecular C-H insertion reactions of α-diazo-β-keto sulfones have predominately focused on the steric and electronic effects of the substituent adjacent to the C-H insertion site using phenyl sulfones. Specifically, we have observed that more sterically demanding groups at the site of insertion lead to higher levels of enantiocontrol.…”

Modern Organic Synthesis with α-Diazocarbonyl Compounds

“…The area of C−H insertion has been extensively reviewed in recent years, 352 372 and with reactivity generally following the order of tertiary > secondary ≫ primary. 365 Highly diastereoselective insertions were also described for reactions employing enantiomerically pure β-ketoesters 369,370 and β-ketoesters with chiral auxiliaries.…”

Efficient Intramolecular C–H Insertion Catalyzed by Iridium Porphyrin Complexes

“…Finally, the Ir(III)-salen complex also promoted the cyclization at room temperature, although with low conversion rates even with long reaction times, resulting in reduced yields by formation of decomposition side products (entry 11). High temperatures and long reaction times increased the conversion degree, but in this case, dimerization was also observed ( Table 2, entries [12][13][14].…”