direct and effective transformation of α-amino ketones, acetamides, and esters to the corresponding α-diazo products under mild basic conditions has been developed. This one-step synthetic approach not only allows for generation of α-substituted-α-diazo carbonyl compounds from α-amino acidderivatives but also permits preparation of α-diazo dipeptides from N-terminal dipeptides (32 examples, up to 91%)
Über die Reaktion von α‐Aminosäure‐
<i>N</i>
‐carbonsäure‐anhydriden mit
<i>N</i>
‐silylierten prim. und sek. Aminen
作者:Hans R. Kricheldorf、Gerd Greber
DOI:10.1002/cber.19711041022
日期:1971.10
Die Umsetzung von Aminosäure-N-carbonsäure-anhydriden (1) (Oxazolidindionen-(2.5)) mit N-silylierten Aminen führt nicht wie dieReaktionmitAminen zu Oligo- oder Polypeptiden. Als Reaktionsprodukte entstehen N-Trimethylsiloxycarbonyl-aminosäure-amide (2) neben Hydantoinsäure-silylestern (12), die nach Hydrolyse als Aminosäureamide (4) und Hydantoinsäuren (5) isoliert wurden. Die Umsetzung N-silylierter
Direct amidation of unprotected amino acids using B(OCH<sub>2</sub>CF<sub>3</sub>)<sub>3</sub>
作者:Rachel M. Lanigan、Valerija Karaluka、Marco T. Sabatini、Pavel Starkov、Matthew Badland、Lee Boulton、Tom D. Sheppard
DOI:10.1039/c6cc05147b
日期:——
A commercially available borate ester, B(OCH2CF3)3, can be used to achieve protecting-group free direct amidation of [small alpha]-amino acids with a range of amines in cyclopentyl methyl ether. The method can...
Simultaneous Deprotection and Purification Based on Ionic Resin Capture: Application to Amide Formations and Grignard and Mitsunobu Reactions
作者:Peter Meier、Sascha Müller
DOI:10.1055/s-2007-983758
日期:——
Tr-protected amines were caught directly out of reaction mixtures by simultaneous cleavage of the protecting group. By releasing the products with ammonia the corresponding free amines were obtained in high yields and purities. The broadly applicable method of simultaneousdeprotection and purificationbased on ionicresincapture was applied for Grignard and Mitsunobu reactions as well as amide formations
A class of compounds that suppress human T-lymphocyte proliferation is disclosed. The active compounds essentially contain at least the following structure: ##STR1##