Synthesis of chiral β-aminophosphine oxides via novel azaboretidinium bromide salts 1
作者:Brian L. Booth、Nicholas J. Lawrence、Humayan S. Rashid
DOI:10.1039/a703936k
日期:——
with sterically demanding groups the azaboretidinium salts are unstable and decompose on work-up. Heating these azaboretidinium salts with aqueous sodium hydroxide in methanol, or better, aqueous sodium hydroxide alone, results in the direct formation of the phosphine oxides, Ph2P(O)CH2CHMeNR1R2 which, in the case of compounds derived from Ipc2BH2, have an ee value of >75%. In some cases, particularly
烯氨基(三苯基)phosph盐[Ph 3 PCH CMeNR 1 R 2 ] + Br – [其中R 1 = R 2 =(CH 2)4,(CH 2)5;(S)-CHMePh;R 1 = H,R 2 =(S)-CHMePh;R 1 = H,R 2 =(S)-(C >> | >> >> H 2)3 -C >> | >> H(CH 2OH)]已合成,并已显示出与过量的硼烷·四氢呋喃反应生成新颖的氮杂硼杂环丁鎓盐,这是四元C–B–N–C杂环的第一个实例。[(1 S,3 R,4 S,1 'S)-4-甲基-1-(1-苯乙基)-1,2-氮杂视黄素-1-基-2-uid-3-基]三苯基phosph的结构溴化物已通过X射线晶体学确定。硼烷在这些还原中不会导致任何明显的立体选择性,而氮杂硼杂环丁鎓盐是非对映异构体的混合物。相比之下,当R 1时,(R)-(+)-单异opinocampheylboran