Enantioselective Hydrogenation of 3-Alkylidenelactams: High-Throughput Screening Provides a Surprising Solution
摘要:
High-throughput screening of 256 potential catalysts (8 metal precursors x 32 phosphine ligands) has identified [(BDPP)Ir(COD)]BF4 as a catalyst for the enantioselective hydrogenation of 3-alkylidenelactams. This result is surprising given the highly flexible backbone of the BDPP ligand and the ineffectiveness of this catalyst in other applications. The asymmetric hydrogenation appears fairly general for five- and six-membered lactams and in one case has been scaled up to a 20 kg level.
Enantioselective Hydrogenation of 3-Alkylidenelactams: High-Throughput Screening Provides a Surprising Solution
摘要:
High-throughput screening of 256 potential catalysts (8 metal precursors x 32 phosphine ligands) has identified [(BDPP)Ir(COD)]BF4 as a catalyst for the enantioselective hydrogenation of 3-alkylidenelactams. This result is surprising given the highly flexible backbone of the BDPP ligand and the ineffectiveness of this catalyst in other applications. The asymmetric hydrogenation appears fairly general for five- and six-membered lactams and in one case has been scaled up to a 20 kg level.
Process for the manufacture of optically active 3-substituted lactams by asymmetric hydrogenation of 3-alkylidenelactams
申请人:——
公开号:US20040010139A1
公开(公告)日:2004-01-15
The present invention relates generally to processes for the efficient production optically active 3-substituted lactams of formula (I)
1
process, comprising:
contacting a compound of formula (II):
2
with hydrogen under a suitable pressure in the presence of an iridium complex of the formula (R
2
)IrL
+
X
−
wherein L is a chelating diene, X is a non coordinating anion, and
R
2
is selected from
3
作者:Tai-Yuen Yue、Douglas D. McLeod、Kevin B. Albertson、Steven R. Beck、Joerg Deerberg、Joseph M. Fortunak、William A. Nugent、Lilian A. Radesca、Liya Tang、Cathie Dong Xiang
DOI:10.1021/op050202l
日期:2006.3.1
A convergent, multikilogram, stereoselective synthesis of 1 is described. A key fragment, (S)-3-(4-fluorobenzyl)piperidine (2) was synthesized from valerolactam in three steps using our recently discovered Ir-BDPP-catalyzed asymmetric hydrogenation. Another key fragment, (IR,2R)-2-(benzyloxycarbonylamino)cyclohexanecarboxaldehyde (3) was synthesized from meso-hexahydrophthalic anhydride in seven steps. The stereochemistry was set in the first step of this sequence via a quinidine-mediated desymmetrization of the meso-anhydride. Coupling of the fragments 2 and 3 followed by deprotection provided the penultimate 23. The active pharmaceutical ingredient (API) free base I was obtained by treatment of 23 with the aminothiazole fragment 4 under mild conditions.
US7015320B2
申请人:——
公开号:US7015320B2
公开(公告)日:2006-03-21
Enantioselective Hydrogenation of 3-Alkylidenelactams: High-Throughput Screening Provides a Surprising Solution
作者:Tai-Yuen Yue、William A. Nugent
DOI:10.1021/ja028043y
日期:2002.11.1
High-throughput screening of 256 potential catalysts (8 metal precursors x 32 phosphine ligands) has identified [(BDPP)Ir(COD)]BF4 as a catalyst for the enantioselective hydrogenation of 3-alkylidenelactams. This result is surprising given the highly flexible backbone of the BDPP ligand and the ineffectiveness of this catalyst in other applications. The asymmetric hydrogenation appears fairly general for five- and six-membered lactams and in one case has been scaled up to a 20 kg level.