Facile and Selective Cleavageof Allyl Ethers Based on Palladium(0)-Catalyzed Allylic Alkylationof<i>N</i>,<i>N</i>′-DimethylbarbituricAcid
作者:Hirokazu Tsukamoto、Yoshinori Kondo
DOI:10.1055/s-2003-39320
日期:——
The classical palladium(0)-catalyzed allylic alkylation of N,N'-dimethylbarbituric acid can be applied to the facile and selective cleavage of allylic alkyl ethers to release the corresponding alcohols in excellent yield.This reaction proceeds under neutral conditions without any additive to activate the allyl ethers and tolerates various functional groups, such as ester, ether, ketone, alkyl and aryl
Alcohols, amines, and thiols protected with a p-cyanobenzyl group can be easily and quantitatively deprotected using triethylgermyl sodium under mild conditions.
p-氰基苄基保护的醇、胺和硫醇可以在温和条件下使用乙基钠锗轻易地实现定量脱保护。
Remarkable Solvent Effect on Pd(0)-Catalyzed Deprotection of Allyl Ethers Using Barbituric Acid Derivatives: Application to Selective and Successive Removal of Allyl, Methallyl, and Prenyl Ethers
Pd(0)-catalyzed deprotection of allylethers using barbituric acid derivatives in protic polar solvent such as MeOH and aqueous 1,4-dioxane proceeds at room temperature without affecting a wide variety of functional groups. Control of the reaction temperature allows selective and successive cleavage of allyl, methallyl, and prenyl ethers. A study of ligand effects on the deprotection reveals that the
A convenient procedure for the regioselective monoprotection of 1,n-diols
作者:Mayumi Takasu、Yuji Naruse、Hisashi Yamamoto
DOI:10.1016/s0040-4039(00)82086-9
日期:——
A method is described for regioselective monoprotection of 1,n-diols. The new process depends on regioselective cleavage of orthoester, which is prepared from 1,n-diols and trialkylorthoesters. The produced mono-acetal is useful in subsequent steps as a normal acetal type protecting group.
Asymmetric Synthesis of Silanediol Inhibitors for the Serine Protease Coagulation Cascade Enzyme FXIa
作者:Hoan Q. Duong、Scott McN. Sieburth
DOI:10.1021/acs.joc.8b00116
日期:2018.5.18
Silanediol peptidomimetics have been prepared, designed to inhibit the serineprotease enzyme Factor XIa (FXIa) for treatment of thrombosis without complete interruption of normal hemostasis. These Arg-[Si]-Ala analogues of the FXIa substrate (FIX) are the first silanediol dipeptide analogues to carry a basic guanidine group. Control of stereochemistry was accomplished using catalytic asymmetric hydrosilylation