• Keine Ergebnisse gefunden

Studies concerning experimental and mechanistic aspects of the domino allylstannylation/

N/A
N/A
Info
Herunterladen
Protected

Academic year: 2021

Aktie "Studies concerning experimental and mechanistic aspects of the domino allylstannylation/ "

Copied!
1
0
0

Wird geladen.... (Jetzt Volltext ansehen)

Jetzt herunterladen ( 1 Seite )

Volltext

(1)

Abstract  

Studies concerning experimental and mechanistic aspects of the domino allylstannylation/

Heck reaction of ortho-iodobenzaldehydes and related structures are described. (1) After the

development of general reaction conditions structurally modified substrates were used and a

broad spectrum of 3-methylene-1-indanols could be synthesised. Beside iodides, triflate and

bromides in situ generated imines also proved to be suitable substrates. (2) Mechanistic

investigations using in situ NMR-spectroscopy and X-ray diffractometry showed strong

evidence for an intermediate palladacycle. A new intramolecular, electrophilic activation

mode was postulated which consists of an activation of the aldehyde function through an

adjacent Lewis-acidic Pd

II

-center. Using control experiments it was shown that

alkoxystannanes proved to be possible base equivalents in Heck reactions. (3) An

enantioselective protocol using a model system could be developed by application of chiral

ligands. A systematic ligand screening revealed Taniaphos to be the optimal chiral ligand

with an induced enantiomeric excess of 96%. The established conditions could be applied to

structural modified substrates. (4) The first steps in the synthesis of the natural product

mutisianthol using the domino allylstannylation/Heck reaction as the key step demonstrates

that this transformation generally serves to build up the required indan structural motif.

Referenzen

Jetzt herunterladen ( PDF - 1 Seite - 53.25 KB )

ÄHNLICHE DOKUMENTE

of the crystals could be noticed.

The aim of the current study was to show variations of Reinke's crystals in patients with cryptorchidism regarding their microscopic appearance using light, confocal and

GENERAL TERMS AND CONDITIONS OF SALE

Without affecting any other rights that it may be entitled to, PSI is enti- tled to terminate any agreement with immediate effect in case of, with- out limitation: (i) default in

A pplying the isotopic substitution technique the spectrum of the normal sample could be interpreted

Matrix Isolation, Isotopic Substitution Technique, Germanium Tetrachloride, Isotopic Splitting Pattern,.. IR

Methodological and technical aspects involved in the development of

The AgroDroughtAustria system combines a GIS model for monitoring yield and grassland drought in Austria (Schaumberger, 2011) and a crop water balance model (Hlavinka,

General Conditions of Sale and Delivery

Events or circumstances beyond the reasonable control of the parties (including our affiliates) and in particular acts of God, fire, explosion, flood, wars, acts of

General Conditions of Sale and Delivery (“Conditions of Sale”)

If purchaser does not notify us of claims within such time period or in the agreed form, our goods or services referred to in such non- compliant notice shall be

General Conditions of Sale and Delivery (“Conditions of Sale”)

If purchaser does not notify us of claims within such time period or in the agreed form, our goods or services referred to in such non-compliant notice shall

General Conditions of Sale and Delivery

17.1 In the event that: (i) the Purchaser is in breach of the Contract (including but not limited to a breach under Clause 16.2); (ii) there is a material change in the