A One-Pot<i>O</i>-Phosphinative Passerini/Pudovik Reaction: Efficient Synthesis of Highly Functionalized α-(Phosphinyloxy)amide Derivatives
作者:Takahiro Soeta、Syunsuke Matsuzaki、Yutaka Ukaji
DOI:10.1002/chem.201304618
日期:2014.4.22
A one‐pot O‐phosphinative Passerini/Pudovikreaction has been developed, based on reacting aldehydes, isocyanides, and phosphinic acids followed by the addition of second aldehydes to form the corresponding α‐(phosphinyloxy)amidederivatives. This is the first reported instance of a Passerini‐type, isocyanide‐based multicomponent reaction using a phosphinic acid instead of a carboxylic acid. The nucleophilicity
triflate and (R,R)-Ph-BOX as a catalyst. This method was successfully applied to a variety of 2-hydroxyalkanamides in high enantioselectivity with up to 92% ee, and then tosylated product was easily transformed into opticallyactive α-amino acid derivatives.
A first example of diphenylborinic acid catalyzed α-addition to isocyanide with aldehyde and water is described. The reaction proceeded smoothly in the presence of water and 5 mol % of borinic acid to give the corresponding α-hydroxyamides in good to high yields. A wide range of aldehydes and isocyanides are applicable to this reaction.
2-hydroxyamide derivatives are produced based on the kineticresolution of racemic 2-hydroxyamides with a diphenylacetyl component and (R)-benzotetramisole ((R)-BTM), a chiral acyl-transfer catalyst, via asymmetric esterification and acylation. It was revealed that a tertiary amide can be used with this novel protocol to achieve high selectivity (22 examples; s-value reaching over 250). The resulting chiral