Organocatalytic asymmetric [4+2] cyclization of 2-benzothiazolimines with azlactones: access to chiral benzothiazolopyrimidine derivatives
作者:Qijian Ni、Xuyang Wang、Fangfang Xu、Xiaoyun Chen、Xiaoxiao Song
DOI:10.1039/d0cc00736f
日期:——
An organocatalytic asymmetricdomino Mannich/cyclization reaction between 2-benzothiazolimines with azlactones has been successfully developed. With the bifunctional squaramide catalyst, this formal [4+2] cyclization occurs with good to high yields and excellent stereoselectivities (up to 99% ee, >20 : 1 dr), providing an efficient and mild access to chiral benzothiazolopyrimidines bearing adjacent
NHC-Catalyzed aerobicoxidativereactions of imines and aldehydes have been developed by using sodium pyruvate as a novel and efficient peroxide scavenger. A structurally diverse set of imidates and amidines has been prepared fromimines using this strategy. This general and efficient strategy features the use of sodium pyruvate as a novel and efficient peroxide scavenger and ambient air as the sole
Organocatalytic Asymmetric Synthesis of Benzothiazolopyrimidines via [4 + 2] Cyclization of 2-Benzothiazolimines and Aldehydes
作者:Xue-Ping Chen、Ke-Qiang Hou、Feng Zhou、Albert S. C. Chan、Xiao-Feng Xiong
DOI:10.1021/acs.joc.0c02499
日期:2021.1.15
We report the direct asymmetric synthesis of pyrimido[2,1-b]benzothiazoles using a commercially available chiral amine catalyst. A variety of 2-benzothiazolimines and aldehydes were well tolerated under the reaction conditions and generated the corresponding products in 81–99% yields with excellent diastereoselectivities and enantioselectivities (up to >20:1 dr, 99% ee). Furthermore, the products could
我们报告了使用市售手性胺催化剂的嘧啶并[2,1- b ]苯并噻唑的直接不对称合成。在反应条件下,各种2-苯并噻唑啉和醛均具有良好的耐受性,并以81-99%的收率生成了相应的产物,具有非对映选择性和对映选择性(最高> 20:1 dr,99%ee)。此外,产品可以轻松转换为其他有用的手性构件。
Highly enantioselective Mannich reactions of imines with tert-butyl acetoacetate catalyzed by squaramide organocatalyst
作者:Hai-Xiao He、Da-Ming Du
DOI:10.1016/j.tetasy.2014.03.010
日期:2014.4
Highly enantioselective Mannich reactions of iminesbearing a benzothiazolemoiety with tert-butyl acetoacetate, catalyzed by a cinchona-based squaramide organocatalyst have been developed. The corresponding benzothiazole β-keto ester derivatives were obtained in high yields (up to 99%) and with excellent enantioselectivities (up to 98% ee).
Organocatalytic enantioselective aza-Friedel–Crafts reaction between benzothiazolimines and 2-naphthols for the preparation of chiral 2′-aminobenzothiazolomethyl naphthols
作者:Chen-Yi Li、Min Xiang、Jian Zhang、Wen-Sheng Li、Ying Zou、Fang Tian、Li-Xin Wang
DOI:10.1039/d1ob01443a
日期:——
developed, and a series of chiral 2′-aminobenzothiazolomethyl naphthols with potential antiproliferative and anthelminticactivities have been successfully and effectively prepared in good to excellent yields (up to 98%) with excellent enantioselectivities (up to >99% ee) even in a scale-up preparation under mild conditions.