Asymmetric hydrogenation reactions mediated by a new class of bicyclic bisphosphinites

详细信息    查看全文

• 作者：Derrien ; Nadine ; Dousson ; Cyril B. ; Roberts ; Stanley M. ; Berens ; Ulrich ; Burk ; Mark J. ; Ohff ; Manuela
• 刊名：Tetrahedron: Asymmetry
• 出版年：1999
• 出版时间：August 27, 1999
• 年：1999
• 卷：10
• 期：17
• 页码：3341-3352
• 全文大小：195 K

文摘

The bicyclic alcohol (−)-4 was prepared from (−)-bicyclo[3.2.0]hept-2-en-6-one (−)-1 in 50 % yield. The diol (−)-4 was coupled to selected chlorophosphines 6–12 to produce a series of bisphosphinites 13–19 in 89–95 % yield. From these bisphosphinites were prepared the rhodium complexes 20–26 which were characterised by ³¹P NMR and used in situ for the asymmetric hydrogenation of b1;-enamides 27–29. Complexes 21, 23–25 proved to be the superior catalysts for the production of (R)-N-acetylphenylalanine (91, 84, 90 and 87.5 % ee) from 27 and (S)-N-acetylalanine methyl ester (70, 72, 68 and 71 % ee) from 28.