Gold-catalyzed [3+3]-annulation of azomethine imines with propargyl esters.
نویسندگان
چکیده
The gold-catalyzed [3+3]-cycloaddition reaction of propargyl esters and azomethine imines has been developed. The reaction provides a rapid entry into a wide range of substituted tetrahydropyridazine derivatives from simple starting materials. A stepwise mechanism involving addition of the 1,3-dipole to a gold-carbenoid intermediate is proposed.
منابع مشابه
Synthesis of azepines by a gold-catalyzed intermolecular [4 + 3]-annulation.
A convenient gold(III)-catalyzed synthesis of azepines from the intermolecular annulation of propargyl esters and alpha,beta-unsaturated imines is reported (19 examples, 55-95% yield). This formal [4 + 3]-cycloaddition reaction is proposed to proceed via a stepwise process involving intramolecular trapping of an allyl-gold intermediate.
متن کاملSynthesis of benzonorcaradienes by gold(I)-catalyzed [4+3] annulation.
A formal [4 + 3]-annulation of vinyl arenes and diynyl propargyl esters is described. A mechanism involving cationic phosphinegold(I)-catalyzed tandem cyclopropanation/hydroarylation to produce the benzonorcaradiene products is proposed. In accord with this mechanism, the alkynyl cyclopropane can also be prepared with excellent regio- and diastereocontrol.
متن کاملPhosphine-catalyzed [3+2] annulation of α-substituted allenoates with ester-activated α,β-unsaturated imines: a novel variation of the Lu [3+2] cycloaddition reaction.
A phosphine-catalyzed [3+2] annulation reaction of α-substituted allenoates with ester-activated α,β-unsaturated imines is reported, which provides new and efficient access to highly functionalized cyclopentenes bearing one all-carbon quaternary center. This reaction also expands the scope of the famous Lu [3+2] cycloaddition reaction.
متن کاملFluorenes and styrenes by Au(I)-catalyzed annulation of enynes and alkynes.
Intermolecular annulation of enynes and propargyl esters to selectively produce styrenes or fluorenes is reported. The divergent arene syntheses involve a Au-catalyzed, two-pot, multistep process proceeding by cis-diastereoselective cyclopropanation, cycloisomerization, and, finally, annulation or elimination.
متن کاملN-Heterocyclic carbene-catalyzed [2+3] cyclocondensation of α-chloroaldehydes with azomethine imines.
An N-heterocyclic carbene-catalyzed enantioselective [2+3] cyclocondensation of α-chloroaldehydes with azomethine imines was developed. The corresponding pyrazolidinones were obtained in good yields with moderate to good diastereoselectivities and excellent enantioselectivities.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of the American Chemical Society
دوره 131 33 شماره
صفحات -
تاریخ انتشار 2009