Highly diastereoselective construction of acyclic systems with two adjacent quaternary stereocenters by allylation of ketones.

نویسندگان

  • Takeshi Takeda
  • Masanori Yamamoto
  • Satoshi Yoshida
  • Akira Tsubouchi
چکیده

Unsymmetrical ketones and allyltitanocenes generated by the desulfurizative titanation of γ,γ-disubstituted allyl phenyl sulfides react under highly diastereoselective construction of adjacent quaternary stereocenters (see scheme; R(L) = large group, R(S) = small group). The title reaction is stereospecific: the anti- and syn-homoallylic alcohols are obtained by the reaction of E- and Z-allylic sulfides, respectively.

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

Highly diastereoselective and enantiospecific allylation of ketones and imines using borinic esters: contiguous quaternary stereogenic centers.

3,3-Disubstituted allylic boronic esters are not sufficiently reactive to react with ketones and imines. However, they can be converted into the corresponding borinic esters by the sequential addition of nBuLi and TFAA. These reactive intermediates possess the perfect balance between reactivity and configurational stability. Their enhanced reactivity allows the highly selective allylation of bo...

متن کامل

Convergent diastereoselective preparation of adjacent quaternary stereocenters in an acyclic system.

The combined carbometalation-zinc homologation-allylation reaction of the resulting stereodefined 3,3-disubstituted allylmetal species with ketones allow the preparation of allylic vicinal diol derivatives in good yields with excellent diastereomeric ratios from commercially available alkynes. Two adjacent quaternary centers are formed with the concomitant formation of three new carbon-carbon b...

متن کامل

Diastereoselective synthesis and spin-dependent photodecarbonylation of di(3-phenyl-2-pyrrolidinon-3-yl)ketones: synthesis of nonadjacent and adjacent stereogenic quaternary centers.

A diastereoselective procedure to obtain N-para-methoxybenzyl bis-alpha,alpha'-3-(3-phenyl-2-pyrrolidinone)yl substituted ketones with non-adjacent quaternary stereocenters, DL-2 and meso-3 was followed by a photoinduced, spin-dependent, and diastereoselective decarbonylation to give compounds DL-4 and meso-5, with adjacent all-carbon quaternary stereogenic centers.

متن کامل

Diastereoselective indium-mediated allylation of N-tert-butanesulfinyl ketimines: easy access to asymmetric quaternary stereocenters bearing nitrogen atoms.

Indium-mediated allylation of N-tert-butanesulfinyl ketimines afforded in high yields and diastereoselectivities homoallylic amine derivatives with the nitrogen atom bonded to a quaternary stereocenter.

متن کامل

A Highly Diastereoselective and Enantioselective Phase-Transfer Catalyzed Epoxidation of β-Trifluoromethyl-β,β-disubstituted Enones with H2O2

Trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.An efficient epoxidation of β-CF3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and F5-substituted chiral qua...

متن کامل

ذخیره در منابع من

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


  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:
  • Angewandte Chemie

دوره 51 29  شماره 

صفحات  -

تاریخ انتشار 2012