Aminomethylation of organic halides promoted by zinc in protic medium
作者:Idália H.S. Estevam、Margarete F. da Silva、Lothar W. Bieber
DOI:10.1016/j.tetlet.2005.08.139
日期:2005.10
halides undergo smooth aminomethylation by secondary amines and aqueousformaldehyde promoted by metallic zinc under copper(I) catalysis. Good to excellent yields are obtained with primary, secondary, and tertiary iodides, allylic, propargylic, and benzylic bromides and with α-bromoesters. In most cases, DMSO is the best solvent, but dioxane is preferable for some more reactive halides. Additional experiments
Practical Synthesis of Natural
Amino Acid Derivatives: Hf(OTf)<sub>4</sub>-Catalyzed Mannich-Type
Reaction of Ketene Silyl Acetals or Enol Silyl Ethers with <i>N</i>,<i>O</i>-Acetals
as a Glycine Cation Equivalent
作者:Norio Sakai、Asuka Sato、Takeo Konakahara
DOI:10.1055/s-0029-1216743
日期:——
The authors demonstrated the Hf(OTf) 4 -catalyzed Mannich-type reaction of an enol silyl ether and a ketene silyl acetal with an N,O-acetat leading to the preparation of amino acid derivatives. In particular, use of the N,O-acetal having a bis(trimethylsilyl)amino group directly produced N-unprotected aspartic acid derivatives after a standard aqueous workup.