Synthesis of α1-oxindole-α-hydroxyphosphonates under catalyst-free conditions using polyethylene glycol (PEG-400) as an efficient and recyclable reaction medium
A simple, efficient, eco-friendly, and cost-effective method has been developed for the synthesis of α1-oxindole-α-hydroxyphosphonate derivatives (3a–o) by a one-pot reaction of isatins (1a–o) with trialkyl phosphites (2a–o) under catalyst-free-conditions using inexpensive, non-toxic polyethyleneglycol (PEG-400) in excellent yields (82–92%). The present methodology offers an environmental acceptability;
alpha(1)-Oxindole-alpha-hydroxyphosphonates were synthesized for the first time in water under neutral conditions mediated by beta-cyclodextrin in high yields. The beta-cyclodextrin can be recovered and reused without any loss of activity. (C) 2010 Elsevier Ltd. All rights reserved.