Iron(II) Halide Promoted Cyclization of Cyclic 2-Enynamides: Stereoselective Synthesis of Halogenated Bicyclic γ-Lactams.

نویسندگان

  • Ming-Chang P Yeh
  • Yuan-Shin Shiue
  • Hsin-Hui Lin
  • Tzu-Yu Yu
  • Ting-Chia Hu
  • Jia-Jyun Hong
چکیده

A simple and mild process was developed for the highly stereoselective synthesis of halogenated bicyclic [4.3.0] and [3.3.0] γ-lactams, possessing four stereocenters, from easily available cyclic 2-enynamides. The reaction required only an inexpensive iron(II) halide under dry air and was tolerant of aryl, heteroaryl, and alkyl groups at the alkyne terminus.

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

Enantioselective formal synthesis of uleine alkaloids from phenylglycinol-derived bicyclic lactams.

A two-step route for the enantioselective construction of the tetracyclic ring system of uleine alkaloids, involving the stereoselective conjugate addition of an appropriate indole-containing nucleophile to a chiral bicyclic delta-lactam and the subsequent cyclization on the indole 3-position of the resulting 4,5-disubstituted 2-piperidone, has culminated in the formal total synthesis of severa...

متن کامل

Carbamoyl Radical-Mediated Synthesis and Semipinacol Rearrangement of β-Lactam Diols

In an approach to the biologically important 6-azabicyclo[3.2.1]octane ring system, the scope of the tandem 4-exo-trig carbamoyl radical cyclization-dithiocarbamate group transfer reaction to ring-fused β-lactams is evaluated. β-Lactams fused to five-, six-, and seven-membered rings are prepared in good to excellent yield, and with moderate to complete control at the newly formed dithiocarbamat...

متن کامل

First total synthesis of ent-gelsedine via a novel iodide-promoted allene N-acyliminium ion cyclization.

The first total synthesis of the oxindole alkaloid gelsedine (1) starting from (S)-malic acid is described. The key step is a novel iodide-promoted intramolecular reaction of an allene with an N-acyliminium ion intermediate which provided in a single step the bicyclic vinyl iodide 11. Other important steps are the highly stereoselective Pd-catalyzed Heck cyclization of N-methylanilide 23a which...

متن کامل

A stereoselective cyclization strategy for the preparation of γ-lactams and their use in the synthesis of α-methyl-β-proline.

A straightforward stereoselective and enantiodivergent cyclization strategy for the construction of γ-lactams is described. The cyclization strategy makes use of chiral malonic esters prepared from enantiomerically enriched monoesters of disubstituted malonic acid. The cyclization occurs with the selective displacement of a substituted benzyl alcohol as the leaving group. A Hammett study illust...

متن کامل

Stereoselective synthesis of 7-epi-incarvilline.

The enantioselective synthesis of 7-epi-incarvilline for formal syntheses of (-)-incarvilline, (+)-incarvine C, and (-)-incarvillateine is described. The key features of our synthesis involve (1) stereoselective construction of the optically active bicyclic lactone utilizing Pd(0)-catalyzed allylic alkylation, (2) efficient transformation of the bridged bicyclic lactone to the key bicyclic lact...

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:
  • Organic letters

دوره 18 10  شماره 

صفحات  -

تاریخ انتشار 2016