Asymmetric Aza-Wacker-Type Cyclization of <i>N</i>-Ts Hydrazine-Tethered Tetrasubstituted Olefins: Synthesis of Pyrazolines Bearing One Quaternary or Two Vicinal Stereocenters
aza-Wacker-type cyclization of N-Ts hydrazine-tethered tetrasubstituted olefins, affording optically active pyrazolines bearing chiral tetrasubstituted carbon stereocenters. This reaction is tolerant to a broad range of substrates under mild reaction conditions, giving the desired chiral products with high enantioselectivities. Generation of two vicinal stereocenters on the C═C double bonds was also achieved
Synthesis of Highly Functionalized Tri- and Tetrasubstituted Alkenes via Pd-Catalyzed 1,2-Hydrovinylation of Terminal 1,3-Dienes
作者:Vaneet Saini、Mark O’Dair、Matthew S. Sigman
DOI:10.1021/ja511640g
日期:2015.1.21
An efficient method for the construction of Csp2–Csp3 bond in a regio- and stereoselective fashion involving 1,3-terminal dienes, enol triflates/nonaflates, and sodium formate under Pd(0)-catalysis is described. The three component assembly allows trapping of a π-allyl intermediate, after the initial migratory insertion of the diene, by a hydride source that leads to structurally complex and synthetically
A PhI(OAc)2-promoted dioxygenation of allyl oximes, including one alkoxylation, has been developed. This reaction can give isoxazoline products bearing two contiguous tetrasubstituted carbons. Various oximes substrates bearing different aryl groups and tetrasubstituted-olefin moieties were compatible with the mild reaction conditions. A two-electron oxidation pathway was proposed based on results of
Substituted imidazoles having angiotensin II receptor blocking activity
申请人:——
公开号:US05312828A1
公开(公告)日:1994-05-17
Angiotensin II receptor antagonists having the formula: ##STR1## which are useful in regulating hypertension and in the treatment of congestive heart failure, renal failure, and glaucoma, pharmaceutical compositions including these antagonists, and methods of using these compounds to produce angiotensin II receptor antagonism in mammals.