Soft Enolization of 3-Substituted Cycloalkanones Exhibits Significantly Improved Regiocontrol vs Hard Enolization Conditions
作者:Natalie C. Dwulet、Vincenzo Ramella、Christopher D. Vanderwal
DOI:10.1021/acs.orglett.1c03844
日期:2021.12.17
markedly better than the typically applied hard enolization protocols for regioselective enoxysilane formation from unsymmetrical 3-substituted cycloalkanones. Five-, six-, and seven-membered cycloalkanones each with 3-methyl, 3-isopropyl, or 3-phenyl substituents were investigated, and in all but one case, regioselectivities were ≥11:1 for enolization away from the substituent. These results are complementary
Unexpected Formation of Trifluoromethylated Spiro or Fused Cyclic Compounds from 4-Ethyloxy-1,1,1-trifluoro-3-buten-2-one and Silyl Enol Ethers
作者:Shizheng Zhu、Huiling Jiang
DOI:10.1055/s-2006-941574
日期:2006.6
Two kinds of trifluoromethylated spiro or fused cyclic compounds were synthesized via the unexpected direct alpha,alpha'-dialkylation of (E)-4-ethoxy-1,1,1-trifluoro-3-buten-2-one (1) with silyl enol ethers in the presence of boron trifluoride etherate.
Preparation of Alkyl Di(<i>p</i>-tolyl)sulfonium Salts and Their Application in Metal-Free C(sp<sup>3</sup>)–C(sp<sup>3</sup>) and C(sp<sup>3</sup>)–C(sp<sup>2</sup>) Bond Formations
Alkyldiarylsulfonium salts were synthesized by a combination of active sulfonium species, prepared through the activation of diarylsulfoxide, and alkyl nucleophiles. The isolated sulfonium salts were subjected to the allylation and cyclopropanation of the active methylene compounds and metal-free C(sp3)–C(sp2) couplings via oxyallyl cation intermediates under mild conditions. The series of reactions