Brønsted Base Catalyzed [2,3]-Wittig/Phospha-Brook Tandem Rearrangement Sequence
摘要:
A Bronsted base catalyzed rearrangement reaction of 2-allyloxy-2-phosphonoacetate derivatives was developed. This reaction proceeded via a [2,3]-Wittig rearrangement followed by a phospha-Brook rearrangement. This is the first example of a catalytic [2,3]-Wittig rearrangement initiated by a Bronsted base.
Brønsted Base Catalyzed [2,3]-Wittig/Phospha-Brook Tandem Rearrangement Sequence
作者:Azusa Kondoh、Masahiro Terada
DOI:10.1021/ol402144q
日期:2013.9.6
A Bronsted base catalyzed rearrangement reaction of 2-allyloxy-2-phosphonoacetate derivatives was developed. This reaction proceeded via a [2,3]-Wittig rearrangement followed by a phospha-Brook rearrangement. This is the first example of a catalytic [2,3]-Wittig rearrangement initiated by a Bronsted base.
Tandem Horner-Wadsworth-Emmons Olefination/Claisen Rearrangement/Hydrolysis Sequence: Remarkable Acceleration in Water with Microwave Irradiation
作者:Ernesto Quesada、Richard J. Taylor
DOI:10.1055/s-2005-918452
日期:——
A tandem three-step, one-pot method for the conversion of aldehydes into β-substituted-2-oxohex-5-enoic acids 1 in good to excellent yield is described. The optimised sequence is carried out in water with microwave irradiation and involves sequential Horner-Wadsworth-Emmons (HWE) olefination, Claisen rearrangement and ester hydrolysis. The outcome of this domino sequence can be controlled by the temperature of the process.