An Efficient Access to Novel Enantiomerically Pure Steroidal δ??Amino Acids

HW Sünnemann, A Hofmeister, J Magull…

Index: Suennemann, Hans Wolf; Hofmeister, Anja; Magull, Joerg; De Meijere, Armin Chemistry - A European Journal, 2006 , vol. 12, # 32 p. 8336 - 8344

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Citation Number: 6

Abstract

Abstract A highly chemoselective sequence of Stille and Heck couplings on the heterocyclic bromoenol triflates 2 a–c with the bicycloalkenylstannanes cis-3 and trans-3 furnished the intermediate bromobutadienes 4 a–c in good yields ranging from 73–94%. A modified Heck coupling protocol employing the palladacycle 8 and an additional bidentate ligand such as 1, 4-bis (diphenylphosphinyl) butane allowed a significant reduction in catalyst loading ...