The synthesis of highly substituted β-lactams was achieved by addition of air-stable ethyl(trimethylsilyl)acetate derivatives to N-(2-hydroxyphenyl)aldimine sodium salts in a THF-EtCN mixture. This reaction proceeds with moderate to good yields and diastereomeric ratio of up to 78:22. The reactivity of the N-(2-hydroxyphenyl)aldimine can be modified by simply changing the co-solvent from EtCN to MeCN to afford the cyanomethylated addition product.
Divergent synthesis of chiral heterocycles via sequencing of enantioselective three-component reactions and one-pot subsequent cyclization reactions
作者:Min Tang、Dong Xing、Haoxi Huang、Wenhao Hu
DOI:10.1039/c5cc01979f
日期:——
A highly efficient sequencing of enantioselective three-component reactions with a variety of one-pot subsequent cyclization reactions was developed.
利用一种高效的三组分选择性合成顺序,开发了一系列一锅法后续环化反应。
Rhodium(II) catalyzed multi-component reactions of aryldiazoacetates with titanium(IV) isopropoxide and imines
作者:Xu Zhang、Na Zhang、Xin Guo、Liping Yang、Wenhao Hu
DOI:10.1016/j.tet.2009.07.049
日期:2009.9
Rh2(OAc)4 catalyzed diazo decomposition of aryldiazoacetates in the presence of titanium(IV) isopropoxide generated oxonium ylide intermediates. Trapping of the oxonium ylide intermediates with imines occurred subsequently via a nucleophilic addition. The three-component reaction of aryldiazoacetates, titanium(IV) isopropoxide, and imines gave α-alkoxyl-β-amino acid derivatives with C–N/C–C bond formation
An enantioselective bisvinylogous Mannich reaction of silyl ketene acetal with aldimines has been realized by using a chiral N,N′‐dioxide/Tm(OTf)3 complex as catalyst, providing an effective method to synthesize chiral ζ‐amino‐α,β,γ,δ‐unsaturated carbonyl compounds.
Reaction of 2- and 4-(Arylmethylideneamino)phenols with Methyl 1-Bromocyclohexanecarboxylate and Zinc
作者:E. A. Nikiforova、D. V. Baibarodskikh、D. P. Zverev、M. V. Dmitriev、N. F. Kirillov
DOI:10.1134/s1070428021080066
日期:2021.8
Abstract 2- and 4-(Arylmethylideneamino)phenols react with Reformatskyreagent, obtained from methyl 1-bromocyclohexanecarboxylate and zinc, to form 3-aryl-2-[2-(or 4-)hydroxyphenyl]-2-azaspiro[3.5]nonan-1-ones. The reaction involves the initial addition of the organozinc reagent across the C=N double bond of the Schiff base and the subsequent intramolecular cyclization of the adduct via the nucleophilic