Diastereoselectivity in the Staudinger reaction: a useful probe for investigation of nonthermal microwave effects

The effect of microwave irradiation on the selectivity, especially stereoselectivity, is one of the most important issues in microwave-assisted organic reactions. The diastereoselectivity in Staudinger reactions involving the representative ketenes and the corresponding matched imines has been used as a probe to investigate carefully the existence of the specific nonthermal microwave effects. The results indicate that the microwave irradiation-controlled stereoselectivity in the Staudinger reaction is in fact the contribution of temperature. No specific nonthermal microwave effect was found in the Staudinger reaction. (C) 2007 Elsevier Ltd. All rights reserved.