Ru(II)‐Pheox Catalyzed Highly Stereoselective Cyclopropanation of Allyl‐ and Vinylsilanes with Diazoesters and Their Synthetic Applications

Abstract

The stereoselective synthesis of optically active cyclopropylsilanes from various allyl‐ and vinylsilanes with functionalized diazoesters was achieved in excellent yields (up to 99 %) and diastereo‐ (up to >99 : 1 d.r.) and enantioselectivities (up to 99 % ee) in the presence of Ru(II)‐Pheox catalysts. Among a series of Ru(II)‐Pheox catalysts, p‐MeO−Ru(II)‐Pheox was determined to be the best catalyst for cyclopropanation reactions of diazoesters with various allylsilanes. Also, methyl(diazoacetoxy)acetate afforded in significantly enhanced yields, diastereoselectivities, and enantioselectivities. The cyclopropanation reactions with vinylsilanes with methyl (diazoacetoxy)acetate proceeded with excellent diastereoselectivities (>99 : 1 d.r.). Moreover, cyclopropylsilane derivatives could be successfully transformed into beneficial building blocks for the synthesis of bioactive compounds, including an anti‐HIV drug and Imatinib‐7.

Fluorocyclopropane-Containing Proline Analogue: Synthesis and Conformation of an Item in the Peptide Chemistʼs Toolbox

“…Rh 2 ((S)-BPTCP) 4 , which has been proven to be a highly efficient Rh catalyst for cyclopropanation, particularly in fluorinated series, delivered the expected cyclopropane from 5c in 92% isolated yield and 70% ee when the reaction was carried out in CHCl 3 at −35 °C (Scheme , entry 13). We next examined the use of Ru-Pheox, which is also very efficient in many cyclopropanation reactions . When Ru-Pheox 3 (Scheme , entry 9) was used in the intramolecular cyclopropanation of 5b at 0 °C, the expected target was obtained with the best ee (77%) and in very good isolated yield (80%).…”

Editorial: The Catalysis of Ring Synthesis

“…The groups of Lu and Cai report a Co‐based heterogeneous catalyst, supported on N,P co‐doped porous carbon (Co@NCP), for the synthesis of quinoxalines from o ‐nitroanilines and biomass‐derived diols [21] . Iwasa and co‐workers report on Ru(II)‐Pheox catalysts for the stereoselective synthesis of optically active cyclopropylsilane derivatives, which could be used as building blocks for the synthesis of bioactive compounds, including an anti‐HIV drug and Imatinib‐7 [22] . The team of Da , Chen and Li reports on Ru‐catalyzed double C(sp 2 )−H functionalizations of fumaramides with alkynes for the synthesis of pyridones and naphthyridinediones [23] .…”

“…[21] Iwasa and co-workers report on Ru(II)-Pheox catalysts for the stereoselective synthesis of optically active cyclopropylsilane derivatives, which could be used as building blocks for the synthesis of bioactive compounds, including an anti-HIV drug and Imatinib-7. [22] The team of Da, Chen and Li reports on Ru-catalyzed double C(sp 2 ) À H functionalizations of fumaramides with alkynes for the synthesis of pyridones and naphthyridinediones. [23] A rhodium(III)-catalyzed [4 + 1] cyclization between anthranils and aroyl sulfoxonium ylides, enabling C À H activation, ring opening of anthranils and oxygen insertion cascade towards Narylisatins is reported by the groups of Li and Jiang.…”

Catalytic Enantioselective Synthesis of Functionalized Cyclopropanes from α‐Substituted Allyl Sulfones with Donor‐Acceptor or Diacceptor Diazo Reagents

“…(Scheme 1, Equation (3)). In 2021, Iwasa [10] (Scheme 1, Equation (4)) disclosed the first general catalytic enantioselective cyclopropanation of allyl silanes, mostly non‐substituted ones, with the methyl (diazoacetoxy)acetate giving the expected cyclopropanes in high yields, good d.r. and excellent ee.…”