ISSN:0570-0833    

DOI:10.1002/anie.199423531

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199423631

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractEmil Fischer's famous lock‐and‐key analogy (Schlüssel‐Schloss‐Prinzip) for the specifity of enzyme action has provided successive generations of scientists with a mental picture of molecular recognition processes, and thus has shaped to a marked degree the development not only of organic chemistry, but, through its extension to basic live processes, that of biology and medicine as well. The hundredth anniversary of the first use of this most fertile metaphor provides a welcome opportunity not only for highlighting its paramount importance, but for gaining an understanding and appreciation of the creative processes involved, of the constructive reasoning and the thought patterns underlying the fundamental insight. Accordingly, this account attempts to trace how Fischer was led to the lock‐and‐key analogy, based on the state of knowledge and the views prevailing at the time. It reveals that Fischer, who had a pronounced tendency against any sort of theoretical speculation, refrained from taking this metaphor any further, that is to the obvious extensions of what turns the key, and what kind of doors are then opened. Except for a small refinement–the differentiation of main key and special keys to account for the fact that some yeasts can ferment a larger number of hexoses than others—he rather expounded on the scope of the lock‐and‐key picture: “I am far from placing this hypothesis side by side to the established theories of our science, and readily admit, that it can only be thoroughly tested, when we are able to isolate the enzymes in a pure state and thus investigate their configuration.” Others, most notably P. Ehrlich und F. Lillie, by introduction of the concept of stereocomplementarity into medicine and biology, induced the lock‐and‐key analogy to become something of a dogma for explain

ISSN:0570-0833    

DOI:10.1002/anie.199423641

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199423751

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe palladium‐catalyzed coupling of haloarenes and haloalkenes with alkenes, which was discovered by Richard F. Heck in the late sixties, has been a topic of fluctuating interest; however, in the last six years activity in this area has flourished. Careful choice of substrates and skillful tailoring of reaction conditions lead to impressive sequences consisting of even different reaction types that occur not only in a consecutive mode, but also in a single operation. The wellestablished Heck reaction, together with other mechanistically related palladiumcatalyzed transformations with arene, alkene, and alkyne derivatives, opens the door to a tremendous variety of elegant and highly convergent routes to structurally complex molecules. The reaction is not disturbed by heteroatoms such as oxygen and nitrogen (nor by sulfur and phosphorus with some limitations). The spectrum of recent achievements starts with a range of chemoselective and regioselective monocouplings of highly functionalized substrates with unsymmetrical and multisubstituted reaction partners. Other advances include cascade reactions in which three, four, five, and even eight new CC bonds are formed to yield oligofunctional and oligocyclic products with impressive molecular complexity. Even the enantioselective construction of complex natural products with quaternary stereocenters has been achieved with Heck reactions in key steps, as exemplified by the synthesis of crinan, picrotoxinin, and morphine. Today, the Heck reaction is indispensible in the arsenal of synthetic methods available to organic chemists. Certainly it is only a matter of time before the Heck reaction is applied in industrial synthe

ISSN:0570-0833    

DOI:10.1002/anie.199423791

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199424131

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199424211

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199424221

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199424241

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199424271

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY