Aromatic C–H Methylation and Other Functionalizations via the Rh(III)-Catalyzed Migratory Insertion of Bis(phenylsulfonyl)carbene and Subsequent Transformations

Abstract

The Rh(III)-catalyzed migratory insertion of bis-(phenylsulfonyl)carbene into aromatic C−H bonds has been developed. A variety of bis(phenylsulfonyl)methyl derivatives were prepared with good yields under mild conditions. The methylated products were readily obtained after reductive desulfonylation. Furthermore, the diverse transformations of bis(phenylsulfonyl)methyl to trideuteriomethyl, aldehyde, and other functional groups were demonstrated.

Rh(iii)-Catalyzed ortho C–H functionalization of aromatic amides with bis(phenylsulfonyl)diazomethane and α-diazosulfones

“…The catalytic system [Cp*RhCl 2 ] 2 /AgSbF 6 , which was used in our previous study, provided 3a in a 27% yield (Table 1, entry 2). 8 The replacement of AgSbF 6 with AgOAc resulted in the complete loss of the catalytic activity (Table 1, entry 3). The use of other silver salts was unsuccessful (Table 1, entries 4–6).…”

“…A variety of nitrogen heterocycles worked as the directing groups (Scheme 1a). 8 The pro-ducts were generally obtained with good yields. The subsequent transformations of bis( phenylsulfonyl)methyl to methyl, trideuteriomethyl, aldehyde, and other functional groups were achieved.…”

Recent advances in transition-metal-catalyzed carbene insertion to C–H bonds

“…The pyridyl moiety of pyridotriazoles plays three vital roles: (a) stabilization of the in situ generated diazo species; (b) acting as a chelating ligand for coordination with the catalyst, facilitating cyclization; (c) as a ligand for detection of metal ions with the products (Scheme 62). Pyridyls, [241][242][243][244] pyrazolyls and oxazolyl, 245 pyrimidyls, [245][246][247] indolyl, 248 and triazolyls 249 can play the same role in regiose-lective aryl C(sp 2 )-H functionalization by carbene insertion.…”

“…With acceptor/donor diazo compound bis(phenylsulfonyl)diazomethane as the carbene precursor under Rh(III) catalysis, aromatic C-H bonds were efficiently functionalized by Nheterocycle-directed carbene insertion. 244 An array of directing N-heteroaryl groups could be applied in the process (Scheme 63). In the presence of equimolar amounts of the C-H substrates and the diazo compound, the target monoalkylated products 193 were obtained in 43-94% yields.…”

“…With acceptor/donor diazo compound bis(phenylsulfonyl)-diazomethane as the carbene precursor under Rh( iii ) catalysis, aromatic C–H bonds were efficiently functionalized by N-heterocycle-directed carbene insertion. 244 An array of directing N-heteroaryl groups could be applied in the process (Scheme 63).…”