Construction of Pyrrolidinyl Spirooxindoles via a 1,3-Dipolar Cycloaddition Reaction of (E)-N-Boc-3-Alkylidene-Indolin-2(3H)ones with Azomethine Ylides
摘要:
A mild and efficient method for the construction of pyrrolidinyl spirooxindoles via a 1,3-dipolar cycloaddition reaction of (E)-N-Boc-3-alkylidene-indolin-2(3H)ones with azomethine ylides has been established. The presence of an N-Boc group in the indolin-2(3H)ones obviously increased the activity and stereoselectivity of the reaction, affording the desired pyrrolidinyl spirooxindoles 4 with up to 85% yield and up to >99/1 dr value. Furthermore, the antibacterial activity of these compounds against Staphylococcus aureus (ATCC-25825) has been tested at minimum concentration, and some of them exhibit moderate antibacterial activity. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for the following free supplemental resource(s): Full experimental and spectral details.]
Enantioselective Construction of Spirooxindole‐Fused Cyclopenta[
<i>c</i>
]chromen‐4‐ones Bearing Five Contiguous Stereocenters via a Stepwise (3+2) Cycloaddition
作者:Sandip Sambhaji Vagh、Praneeth Karanam、Cheng‐Chieh Liao、Ting‐Han Lin、Yan‐Cheng Liou、Athukuri Edukondalu、Yi‐Ru Chen、Wenwei Lin
DOI:10.1002/adsc.201901655
日期:2020.4.17
The bifunctional quinine‐catalyzed stepwise (3+2) cycloaddition for the enantioselective construction of spirooxindole‐fused cyclopenta[c]chromen‐4‐ones is developed. The reactions of 3‐homoacylcoumarins and alkylidene oxindole electrophiles generate aforementioned spirooxindole‐chromenone adducts bearing five contiguous stereocenters, of which one is the spiro all‐carbon quaternary stereocenter in