Chemoselective Synthesis of<i>N</i>-Substituted α-Amino-α′-chloro Ketones<i>via</i>Chloromethylation of Glycine-Derived Weinreb Amides
作者:Vittorio Pace、Wolfgang Holzer、Guido Verniest、Andrés R. Alcántara、Norbert De Kimpe
DOI:10.1002/adsc.201201043
日期:2013.3.25
Functionalized α‐arylamino‐α′‐chloro ketones are obtained in high yield via a straightforward homologation reaction of Weinrebamides derived from N‐arylglycines using in situ generated chloromethyllithium. The use of the Weinrebamides is essential and allows the chemoselective homologation of N‐aryl‐N‐substituted glycine analogues, a transformation which is not possible using similar glycine esters. The
Transition-metal-free decarboxylation of dimethyl malonate: an efficient construction of α-amino acid esters using TBAI/TBHP
作者:Jie Zhang、Ying Shao、Yaxiong Wang、Huihuang Li、Dongmei Xu、Xiaobing Wan
DOI:10.1039/c5ob00109a
日期:——
A new strategy has been developed for the synthesis of α-amino acid esters via a tandem hydrolysis/decarboxylation/nucleophilic substitution using TBAI/TBHP.
已开发出一种新的策略,通过使用TBAI/TBHP进行串联水解/脱羧/亲核取代合成α-氨基酸酯。
Reaction of methyl diazoacetate with aldehydes, amines, thiols, alcohols and acids over transition metal-exchanged clays
Metal-exchanged clays (M = Rh and Cu) catalyze effectively the reaction of methyl diazoacetate with various aldehydes, affording the corresponding β-keto esters in high yields. They have also been effective in the decomposition of methyl diazoacetate to form metallocarbenes which, in turn, successfully insert into X–H (X = N, O, S, CO2) bonds of a variety of amines, aldehydes, thiols and acids, thereby producing the corresponding esters.
[EN] A PROCESS FOR INDUSTRIALLY VIABLE PREPARATION OF (S,S,S) PHENYLMETHYL-2-AZABICYCLO-[3.3.0]-OCTANE-3-CARBOXYLATE TOSYLATE<br/>[FR] PROCEDE DE PREPARATION INDUSTRIELLEMENT VIABLE DE (S,S,S) PHENYLMETHYL-2-AZABICYCLO-[3.3.0]-OCTANE-3-CARBOXYLATE TOSYLATE
申请人:BABU POTLURI RAMESH
公开号:WO2005049568A1
公开(公告)日:2005-06-02
A process for industrially viable preparation of a hitherto unreported intermediate viz., [s, s, s] phenylmethyl -2-azabicyclo [3.3.0]-octane-3-carboxylae tosylate by reacting methyl-N-acetyl- R-chloro alaninate of formula-II with 1-(1-pyrrolidinyl)-cyclopentene of formula (III) in an aprotic solvent using an organic base at 0-50°C and hydrolyzing and cyclizing the compound of formula (IV) and hydrogenating the compound of formula (V) to give a product of formula (VI) viz., 2-azabicyclo [3.3.0] octane 3-carboxylic acid tosylate. Esterifying the product of formula (VI) to give racemic phenylmethyl 2-azabicyclo [3.3.0] octane-3-carboxylate tosylate of formula (VII). Resolving the amino acid ester with an optically active acid, separating the diastereomeric salt, breaking it and converting it to a salt of formula (I).
The invention relates to fragrant mixtures comprising at least one compound of general formula (I), a method for producing claimed fragrant mixtures, particularly perfume oils, perfumed products containing the claimed fragrant mixture, and the use of the compound of general formula (I) to strengthen the natural freshness and/or emanation and/or to mask or reduce greasy and/or metallic notes of one or more fragrant substances that differ from the compound of formula (I).