4-Chloro-5 H -1,2,3-dithiazol-5-one:一种很好的α,β-不饱和β-氨基酯的α-硫氰化剂
摘要:
在120°C下于DMSO中用3-烷基(或芳基)-3-氨基-2-丙烯酸酯处理4-氯-5 H -1,2,3-二噻唑-5-酮,得到相应的2-硫氰酸酯4(主要)和5-烷氧基羰基-4-烷基(或芳基)-4-噻唑啉-2-酮5(次要),而在相同条件下在C-3带有强吸电子基团的酯得到5和/或4-取代的5-烷氧基羰基-2-氨基噻唑6,取决于吸电子基团。
Copper-Catalyzed One-pot Synthesis of Pyrimidines from Amides, <i>N</i>
,<i>N</i>
′-dimethylformamide dimethylacetal, and Enamines
作者:Hitesh B. Jalani、Wangshui Cai、Hongjian Lu
DOI:10.1002/adsc.201700234
日期:2017.7.17
versatile copper catalyzed one‐pot synthesis of diversely substituted pyrimidines directly fromamides, N,N′‐dimethylformamide dimethylacetal (DMF−DMA) and enamines has been established. The reaction involved the two C−N bonds and one C−C bond formation by formal [2+1+3] annulation approach to pyrimidines. This protocol is based on the use of readily available primary amides, DMF−DMA and enamines to
Late-Stage C–H Alkylation of Heterocycles and 1,4-Quinones via Oxidative Homolysis of 1,4-Dihydropyridines
作者:Álvaro Gutiérrez-Bonet、Camille Remeur、Jennifer K. Matsui、Gary A. Molander
DOI:10.1021/jacs.7b05899
日期:2017.9.6
heterocyclic bases and 1,4-quinones. DHPs are readily prepared from aldehydes, and considering that aldehydes normally require harsh reaction conditions to take part in such transformations, with mixtures of alkylated and acylated products often being obtained, this net decarbonylative alkylation approach becomes particularly useful. The present method takes place under mild reaction conditions and requires
[EN] PYRIDINE COMPOUNDS AS INHIBITORS OF DIPEPTIDYL PEPTIDASE IV<br/>[FR] COMPOSES PYRIDINES UTILISES COMME INHIBITEURS DE DIPEPTIDYLE PEPTIDASE IV
申请人:TAKEDA PHARMACEUTICAL
公开号:WO2005042488A1
公开(公告)日:2005-05-12
A compound represented by the formula wherein R1 and R2 are the same or different and each is an optionally substituted hydrocarbon group or an optionally substituted hydroxy group; R3 is an optionally substituted aromatic group; R4 is an optionally substituted amino group; L is a divalent chain hydrocarbon group; Q is a bond or a divalent chain hydrocarbon group; and X is a hydrogen atom, a cyano group, a nitro group, an acyl group, a substituted hydroxy group, an optionally substituted thiol group, an optionally substituted amino group or an optionally substituted cyclic group; provided that when X is an ethoxycarbonyl group, then Q is a divalent chain hydrocarbon group. The compound has a peptidase inhibitory action, is useful as an agent for the prophylaxis or treatment of diabetes and the like, and is superior in efficacy, duration of action, specificity, lower toxicity and the like.
Alkanoate esters are found to couple with various nitriles to give (Z)-3-amino-2-alkenoates in good yields with the aid of a magnesium amide prepared by the reaction of ethylmagnesium bromide and diisopropylamine. The C–C bond forming reaction was applied to (2S,3S)-2,3-(cyclohexylidenedioxy)butanenitrile and the resulting adduct was successfully converted into N-benzoyl-L-daunosamine in 41% overall
Synthesis of tetrasubstituted pyridines by the acid-catalysed Bohlmann–Rahtz reaction
作者:Mark C. Bagley、Christian Brace、James W. Dale、Maren Ohnesorge、Nathan G. Phillips、Xin Xiong、Justin Bower
DOI:10.1039/b203397f
日期:2002.7.11
New facile experimental procedures for the preparation of 2,3,4,6-tetrasubstituted pyridines in a single synthetic step have been developed. Thus, an enamino ester and alkynone react by Michael additionâcyclodehydration in a heterocyclisation process that is catalysed by acetic acid, Amberlyst 15 ion exchange resin, zinc(II) bromide or ytterbium(III) triflate. The new one-step Brønsted or Lewis acid-catalysed BohlmannâRahtz reaction is a simple, direct and highly expedient method for the synthesis of pyridines that proceeds at a lower reaction temperature and avoids the need to isolate reaction intermediates.