Gold(I)-catalyzed enantioselective [3+2] and [3+3] cycloaddition reactions of propargyl acetals/ketals.

نویسندگان

  • Cristina Navarro
  • Nathan D Shapiro
  • Maurizio Bernasconi
  • Takahiro Horibe
  • F Dean Toste
چکیده

An asymmetric gold(I)-catalyzed [3+2] cycloaddition of propargyl acetals/ketals and aldehydes is reported, which proceeds via stepwise migration-fragmentation of acetals/ketals and cycloaddition of the in situ generated gold-carbenoid intermediate. Various functionalized 2, 5-dihydrofurans were obtained in good yields and high enantioselectivities. Furthermore, an example of the first gold(I) catalyzed [3+3] cycloaddition of secondary propargyl ketals and nitrones is presented.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Gold(I)-catalyzed dearomative Rautenstrauch rearrangement: enantioselective access to cyclopenta[b]indoles.

A highly enantioselective dearomative Rautenstrauch rearrangement catalyzed by cationic (S)-DTBM-Segphosgold(I) is reported. This reaction provides a straightforward method to prepare enantioenriched cyclopenta[b]indoles. These studies show vast difference in enantioselectivity in the reactions of propargyl acetates and propargyl acetals in the chiral ligand-controlled Rautenstrauch reaction.

متن کامل

Gold(I)-catalyzed enantioselective [4 + 2]-cycloaddition of allene-dienes.

An enantioselective gold(I)-catalyzed intramolecular [4 + 2]-cycloaddition of allenes and dienes is reported. The reactions allow for the asymmetric synthesis of trans-hexahydroindenes and pyrrolidine products using C(3)-symmetric phosphitegold(I) and ortho-arylphosphoramiditegold(I) complexes as catalysts, respectively.

متن کامل

Highly diastereo- and enantioselective Cu-catalyzed [3 + 3] cycloaddition of propargyl esters with cyclic enamines toward chiral bicyclo[n.3.1] frameworks.

A new Cu-catalyzed asymmetric [3 + 3] cycloaddition of propargyl esters with cyclic enamines is reported. With a combination of Cu(OAc)(2)·H(2)O and a chiral tridentate ferrocenyl-P,N,N ligand as the catalyst, perfect endo selectivities (endo/exo > 98/2) and excellent enantioselectivities (up to 98% ee) for endo cycloadducts were achieved under mild conditions. This method provides a simple and...

متن کامل

Gold(I)-catalyzed enantioselective cycloaddition reactions

In recent years there have been extraordinary developments of gold(I)-catalyzed enantioselective processes. This includes progress in the area of cycloaddition reactions, which are of particular interest due to their potential for the rapid construction of optically active cyclic products. In this article we will summarize some of the most remarkable examples, emphasizing reaction mechanisms an...

متن کامل

Gold-catalyzed [3+3]-annulation of azomethine imines with propargyl esters.

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.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Tetrahedron

دوره 71 35  شماره 

صفحات  -

تاریخ انتشار 2015