Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,a...Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,and broad substrate compatibility,thereby demonstrating great potential for the synthesis of glycoconjugates.Additionally,this method provides an alternative approach for addressing the challenging task of esterifying sterically hindered secondary hydroxyl group of carbohydrates and paving the way for advancements in carbohydrate-based pharmaceuticals.展开更多
利用实验室筛选得到的高立体选择性脂肪酶产生菌株溜曲霉(Aspergillus tamarii WYC3)不对称水解拆分N-BOC-DL-α-氨基丁酸甲酯得到N-BOC-L-α-氨基丁酸,对其反应条件进行研究,确定其最优反应条件为:0.1 mol/L p H 7.2的磷酸钾缓冲液,反...利用实验室筛选得到的高立体选择性脂肪酶产生菌株溜曲霉(Aspergillus tamarii WYC3)不对称水解拆分N-BOC-DL-α-氨基丁酸甲酯得到N-BOC-L-α-氨基丁酸,对其反应条件进行研究,确定其最优反应条件为:0.1 mol/L p H 7.2的磷酸钾缓冲液,反应温度30℃,底物浓度52.24 mmol/L,0.1 g菌粉,V(底物)∶V(丙酮)=1∶8,200 r/min恒温水浴反应6 h,可获得产物N-BOC-L-α-氨基丁酸,此时e.e._(s)值达到99.95%,对映体选择率E值为20.11,产率为36.21%。展开更多
As an important protective group of amines and amino acids,tert-butoxycarbonyl(Boc) group was extensively used in organic synthesis.Though many mild and selective reagents could be used,there is still a need for the d...As an important protective group of amines and amino acids,tert-butoxycarbonyl(Boc) group was extensively used in organic synthesis.Though many mild and selective reagents could be used,there is still a need for the development of a more simple and convenient method for deprotection.In this paper,a new method for the deprotection of N-Boc group with silica gel in refluxing toluene was reported.The reactions were mostly achieved in 5 h with high yields(75%-98%).N-Boc protected indoline and benzylamine,which are not deprotected with other mild method,could be deprotected with our method in good yields(89% and 95%,respectively).Additionally the deprotection of other carbamates such as Cbz,Fmoc and ethyl carbamate wasn′t observed under same conditions.展开更多
文摘Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,and broad substrate compatibility,thereby demonstrating great potential for the synthesis of glycoconjugates.Additionally,this method provides an alternative approach for addressing the challenging task of esterifying sterically hindered secondary hydroxyl group of carbohydrates and paving the way for advancements in carbohydrate-based pharmaceuticals.
文摘As an important protective group of amines and amino acids,tert-butoxycarbonyl(Boc) group was extensively used in organic synthesis.Though many mild and selective reagents could be used,there is still a need for the development of a more simple and convenient method for deprotection.In this paper,a new method for the deprotection of N-Boc group with silica gel in refluxing toluene was reported.The reactions were mostly achieved in 5 h with high yields(75%-98%).N-Boc protected indoline and benzylamine,which are not deprotected with other mild method,could be deprotected with our method in good yields(89% and 95%,respectively).Additionally the deprotection of other carbamates such as Cbz,Fmoc and ethyl carbamate wasn′t observed under same conditions.
