Metal-free, organocatalytic cascade formation of C–N and C–O bonds through dual sp<sup>3</sup>C–H activation: oxidative synthesis of oxazole derivatives
An organocatalytic cascade reaction that involves the formation of C-N, C-O and C=N bonds in one process via dual sp(3) C-H activation has been developed. This protocol affords a facile metal-free methodology for the synthesis of oxazole derivatives in air under mild conditions.
DDQ-promoted direct C5-alkylation of oxazoles with alkylboronic acids via palladium-catalysed C–H bond activation
作者:Bowen Lei、Xiaojiao Wang、Lifang Ma、Huixuan Jiao、Lisi Zhu、Ziyuan Li
DOI:10.1039/c7ob01083d
日期:——
A novel and concise C5-alkylation of oxazole using alkylboronic acids as the alkyl donor via Pd(II)-catalysed C-H bond activation has been achieved in moderate to good yields with satisfactory functional group tolerance. Instead of commonly used BQ as a key promoter, DDQ was discovered to be a better additive that significantly promoted this alkylation. This efficient and advanced method represents
Disclosed is a compound represented by the formula (1) below which has a high DPP-IV inhibitory activity and is improved in safety, toxicity and the like. Also disclosed is a prodrug of such a compound and pharmaceutically acceptable salts of them.
(In the formula, R
1
represents a hydrogen atom, an optionally substituted alkyl group or the like; R
2
and R
3
independently represent a hydrogen atom, an optionally substituted alkyl group or the like; R
4
and R
5
independently represent a hydrogen atom, an optionally substituted alkyl group or the like: R
6
represents a hydrogen atom, an optionally substituted aryl group or the like; and —Y—NH
2
, represents a group represented by the following formula (A):
(wherein m is 0, 1 or 2; and R
7
may not exist or one or two R
7
may exist and independently represent an optionally substituted alkyl group or the like) or the like.]
Facile Synthesis of Polysubstituted Oxazoles via A Copper-Catalyzed Tandem Oxidative Cyclization
作者:Changfeng Wan、Jintang Zhang、Sujing Wang、Jinmin Fan、Zhiyong Wang
DOI:10.1021/ol100688c
日期:2010.5.21
A highly efficient synthesis of polysubstituted oxazoles was developed via a copper-catalyzed tandem oxidative cyclization. The desired products can be obtained from readily available starting materials under mild conditions. This is an attractive alternative method for the synthesis of oxazole derivatives.
A Highly Efficient Heterogeneous Copper-Catalyzed Oxidative Cyclization of Benzylamines and 1,3-Dicarbonyl Compounds To Give Trisubstituted Oxazoles
作者:Li Wei、Shengyong You、Yuxin Tuo、Mingzhong Cai
DOI:10.1055/s-0037-1610710
日期:2019.8
yields. This heterogeneous copper catalyst can be facilely prepared via a simple two-step procedure from readily available and inexpensive reagents and exhibits a slightly higher activity than Cu(OAc)2. MCM-41-2N-Cu(OAc)2 is also easy to recover and can be recycled up to eight times with almost consistent activity. The reaction is the first example of heterogeneous copper-catalyzed intermolecular cyclization