Development of a New and Practical Route to Chiral 3,4-Disubstituted Cyclopentanones: Asymmetric Alkylation and Intramolecular Cyclopropanation as Key C−C Bond-Forming Steps
摘要:
An efficient and practical asymmetric synthesis of (+)-trans-3-hydroxymethyl-4-(3-fluorophenyl)cyclopentanone (1) is described. An asymmetric Mo-catalyzed alkylation reaction was used to establish the first stereocenter and a Cu-catalyzed intramolecular diastereoselective cyclopropanation reaction was used to set the second stereocenter. The last step involved a one-pot ring-opening/deprotection/hydrolysis/decarboxylation sequence that furnished the desired product in good yield.
An Ir-catalyzed asymmetric allylic alkylation using chiral diaminophosphine oxide is described. Asymmetric allylic alkylation of terminal allylic carbonates proceeded using 5 mol % of Ir catalyst, 5 mol % of DIAPHOX 1i, 10 mol % of NaPF6, 10 mol % of LiOAc, and N,O-bis(trimethylsilyl)acetamide (BSA), affording the corresponding branched products in excellent yield and in up to 95% ee. The developed
N-cyclopentyl modulators of chemokine receptor activity
申请人:——
公开号:US20020120146A1
公开(公告)日:2002-08-29
The present invention is directed to compounds of the formula I:
1
(wherein R
1
, R
3
, R
4
, R
5
, R
6
, R
7
, R
8
, X, n, x and y are defined herein) which are useful as modulators of chemokine receptor activity. In particular, these compounds are useful as modulators of the chemokine receptors CCR-5 and/or CC R-3.