novel semipinacol rearrangement using dibromocyclopropanes as sources of carbocations was developed. Heating dibromocyclopropanes bearing a 1‐hydroxyalkyl group with silver perchlorate and 2,6‐lutidine induced cleavage of the cyclopropane ring to form allyl cations, which underwent 1,2‐shift of a substituent at the α‐position of the hydroxygroup to give β,γ‐unsaturated carbonylcompounds having a quaternary
Asymmetric Diels-Alder Reaction of α-Substituted and β,β-Disubstituted α,β-Enals via Diarylprolinol Silyl Ether for the Construction of All-Carbon Quaternary Stereocenters
作者:Yujiro Hayashi、Bojan P. Bondzic、Tatsuya Yamazaki、Yogesh Gupta、Shin Ogasawara、Tohru Taniguchi、Kenji Monde
DOI:10.1002/chem.201602345
日期:2016.10.24
Diels–Alder reaction of α‐substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl‐substituted diarylprolinol silylether to afford the exo‐isomer with both excellent diastereoselectivity and high enantioselectivity. In the Diels–Alder reaction of a β,β‐disubstituted α,β‐unsaturated aldehyde, good exo‐selectivity and excellent enantioselectivity was obtained when the
Enamine protonation: A chiral diamine catalyzes an asymmetric Friedel–Crafts reaction through catalytic enantioselectiveprotonation of an enamine. This process can be applied to a range of α‐substituted acroleins and indoles with high yields of products and high enantioselectivity (up to 94 % ee). An OH/π interaction between H2O and the indole ring was found to play an important role in the transition
烯胺质子化:手性二胺通过烯胺的对映选择性质子化催化不对称的Friedel-Crafts反应。该方法可用于一系列α-取代的丙烯醛和吲哚,具有高收率和高对映选择性(最高94%ee)。的O H / H之间的π相互作用2 O和吲哚环,发现发挥在过渡状态中起重要作用(参见方案)。
Asymmetric Epoxidation of α-Substituted Acroleins Catalyzed by Diphenylprolinol Silyl Ether
作者:Bojan P. Bondzic、Tatsuya Urushima、Hayato Ishikawa、Yujiro Hayashi
DOI:10.1021/ol102269s
日期:2010.12.3
Asymmetric epoxidation of α-substituted acroleins with hydrogen peroxide has been catalyzed by diphenylprolinol diphenylmethylsilyl ether to afford α-substituted-β,β-unsubstituted-α,β-epoxy aldehyde with excellent enantioselectivity and the generation of a chiral quaternary carbon center. The method was applied to a short synthesis of (R)-methyl palmoxirate.
Amine-based and amide-based inhibitors of semicarbazide-sensitive amine oxidase (SSAO)enzyme activity and VAP-1 mediated adhesion useful for treatment of diseases
申请人:Salter-Cid M. Luisa
公开号:US20070078157A1
公开(公告)日:2007-04-05
Compositions and methods are disclosed for inhibiting semicarbazide-sensitive amine oxidase (SSAO), also known as vascular adhesion protein-1 (VAP-1). The compounds disclosed are amine-containing and amide-containing compounds. The compounds and compositions are useful for treatment of diseases, including inflammation, inflammatory diseases and autoimmune disorders.