Cyclopropanation of Alkenes, N–H and S–H Insertion of Ethyl Diazoacetate Catalysed by Ruthenium Porphyrin Complexes

Iron(III) Corroles and Porphyrins as Superior Catalysts for the Reactions of Diazoacetates with Nitrogen‐ or Sulfur‐Containing Nucleophilic Substrates: Synthetic Uses and Mechanistic Insights

“…The results summarized in Table 6 (0.1 mol % catalyst) show that both thiophenols (entries 1-5) and nonaromatic thiols (entries 6 and 7) are converted very quickly and in very high yields into the expected SÀH insertion products, a-thio ethyl ester derivatives (Scheme 12). [8,38] The reactions were very fast (see picture in Scheme 12), and even the less reactive EDP reacted quickly with thiophenol (entries 8 and 9) to provide 20 c.…”

“…[5] These catalysts were overshadowed by [Rh 2 A C H T U N G T R E N N U N G (OAc) 4 ], developed as a catalyst in the 1970s by Paulissen et al [6] However, both the earlier and the more recently developed copper-, silver-, gold-, and ruthenium-based catalysts are usually required in amounts of 1 to 10 mol % and suffer from one or more of the following limitations: gradual addition of the diazo compound to avoid dimerization byproducts, gradual addition of the amine to avoid catalyst poisoning, long reaction times, and low-to-moderate chemical yields. [2,[7][8][9] Decade-long efforts were devoted to the development of catalysts for enantioselective metal-carbene insertion into N À H bonds. Chiral auxiliaries served quite well for inducing rhodium-catalyzed asymmetric intramolecular N À H insertion (optically active proline derivatives were obtained), [10] but their extension to intermolecular reactions met with very limited success.…”

Synthesis and chemical reactivity of new zinc porphyrin diazoacetates catalyzed by ruthenium and iron porphyrins

“…6 In all these cases, the diazo group is directly inserted in the core yielding chlorin derivatives and to our knowledge, there is no diazo group directly appended to the periphery of the porphyrin ring. We previously reported the use of metalloporphyrins for catalytic insertion of diazo compounds in N-H bonds, 7,8 including insulin protein. 9 Asymmetric cyclopropanation was also developed using chiral iron and ruthenium porphyrins as catalysts.…”

“…22 The insertion of electrophilic carbenes in the N-H bonds of protected -amino esters or amides is a powerful method for N-alkylating this class of compounds. 23 Since we 7,8 and others [24][25][26][27] previously reported N-H insertion of diazoesters catalyzed by metalloporphyrins (Fe, Ru), N-H insertion with a diazo porphyrin ester was also investigated (Scheme 2). The results presented in Scheme 2 show that the iron complex is a good catalyst for the transformation of tryptophan methyl ester into the expected N-H inserted products with 69%…”

“…Treatment of thiophenol with diazoporphyrin ester catalyzed by complex 1a gave insertion of the diazo derivative into the S-H bond with 85 % yield. The mechanisms of the cyclopropanation reaction, N-H insertion and S-H insertion, catalyzed by metalloporphyrins, have been previously discussed by us 8 and others [25][26][27] several times, and will not be presented herein. All the new derivatives were identified by NMR and mass spectral analysis.…”