Herein we report the asymmetric synthesis of (3S)-(tert-butyldimethylsilyloxy)methylcyclopentan-1-one (S)-3 as a practical chiral synthon for a wide range of pharmaceutical and/or natural products, using Lipshutz's asymmetric copper-catalyzed conjugate reduction. This method makes it feasible to prepare a conformationally constrained cyclopentane analogue 12, which is one of the key intermediates for the synthesis of novel sphingosine 1-phosphate-1 receptor agonists. (C) 2013 Elsevier Ltd. All rights reserved.
Suzuki–Miyaura cross-coupling reaction of aryl and heteroaryl pinacol boronates for the synthesis of 2-substituted pyrimidines
作者:Shigehiro Asano、Seiji Kamioka、Yoshiaki Isobe
DOI:10.1016/j.tet.2011.10.057
日期:2012.1
Suzuki–Miyauracross-couplingreaction with 2-heteroarylboronic acids is generally challenging due to these acids easy decomposition. To overcome this problem, we developed a coupling method that uses 2-heteroaryl pinacol boronates in the presence of 1.0 mol % Pd(OAc)2 and 2.0 mol % S-Phos with 4 equiv amount of LiOH in dioxane and H2O at 80 °C for 30 min. This developed method allowed for the synthesis