1,4-Addition of arylboronic acids to β-aryl-α,β-unsaturated ketones and esters catalyzed by a rhodium(I)–chiraphos complex for catalytic and enantioselective synthesis of selective endothelin A receptor antagonists
作者:Takahiro Itoh、Toshiaki Mase、Takashi Nishikata、Tetsuji Iyama、Hiroto Tachikawa、Yuri Kobayashi、Yasunori Yamamoto、Norio Miyaura
DOI:10.1016/j.tet.2006.07.075
日期:2006.10
An enantioselective synthesis of acyclic β-diaryl ketones and esters via 1,4-addition of arylboronic acids to β-aryl-α,β-unsaturated ketones or esters is described. The complex in situ prepared from [Rh(nbd)2]BF4 and chiraphos was found to be an excellent catalyst to achieve high enantioselectivities in a range of 83–89% ee for the ketone derivatives and 78–94% ee for tert-butyl β-arylacrylate derivatives
描述了通过芳基硼酸的1,4-加成至β-芳基-α,β-不饱和酮或酯的对映选择性合成无环β-二芳基酮和酯。从制备的原位复合物的[Rh(NBD)2 ] BF 4和CHIRAPHOS被发现是一种极好的催化剂,以实现高的对映选择性为酮衍生物和78-94%ee的对一系列83-89%ee的的叔- β-芳基丙烯酸丁酯的衍生物。该协议为选择性内皮素A受体拮抗剂(的对映选择性合成提供了一种催化方法7,8)由SmithKline Beecham和Merck–Banyu报道。基于DFT计算结果,对烯酮底物与苯基铑(I)–(-)配位的模式进行了研究,讨论了β-芳基-α,β-不饱和酮和酯的手性磷配体的对映体选择机理和效率。S,S)-chiraphos络合物。