Direct ionic liquid promoted organocatalyzed diazo-transfer reactions: diversity-oriented synthesis of diazo-compounds
作者:Dhevalapally B. Ramachary、Vidadala V. Narayana、Kinthada Ramakumar
DOI:10.1016/j.tetlet.2008.02.159
日期:2008.4
A practical and novel ionic liquid promoted organocatalytic selective diazo-transfer process for the synthesis of highly substituted diazo-compounds in high yields is reported. The ionic liquid can be reused without affecting the reaction rates or yields over five runs.
Organic Photocatalytic Cyclization of Polyenes: A Visible-Light-Mediated Radical Cascade Approach
作者:Zhongbo Yang、Han Li、Long Zhang、Ming-Tian Zhang、Jin-Pei Cheng、Sanzhong Luo
DOI:10.1002/chem.201503118
日期:2015.10.12
A visible‐light‐mediated, organic photocatalytic stereoselective radical cascade cyclization of polyprenoids is described. The desired cascade cyclization products are achieved in good yields and high stereoselectivities with eosin Y as photocatalyst in hexafluoro‐2‐propanol. The catalyst system is also suitable for 1,3‐dicarbonyl compounds, which require only catalytic amounts of LiBr to promote the
Tin triflate promoted synthesis of bicyclic and tricyclic sulfonyl dihydropyrans
作者:Chieh-Kai Chan、Yu-Hsin Chen、Meng-Yang Chang
DOI:10.1016/j.tet.2016.07.009
日期:2016.8
Tin triflate-promoted one-pot intramolecular annulation of α-geranyl or α-farnesyl β-ketosulfones 3–4 affords the respective bicyclic or tricyclic sulfonyl dihydropyrans 5–6 in moderate to good yields via a cascade cation-olefin-carbonyl carbocyclization process. The starting materials 3 and 4 were obtained by K2CO3-mediated α-geranylation or α-farnesylation of β-ketosulfones 1 with bromides 2a or
锡,三氟甲磺酸促进的α -香叶基或一锅分子内成环α -法呢β-酮砜3 - 4次,得到相应的二环或三环磺酰基二氢吡喃5 - 6经由级联阳离子烯烃-羰carbocyclization过程在中度至良好的产率。原料3和4是通过K 2 CO 3介导的β-酮砜1与溴化物2a或2b的α-香叶基化或α-法尼基化获得的。关键产物的结构通过X射线晶体学确认。