For understanding the mechanism involved in the Wittig reaction, it is important to know the factors which influence the stability of 1,2-oxaphosphetane intermediates with pentacoordinate phosphorus; in these intermediates, the steric factor plays a predominant role. Studying the Wittig reaction between nonstabilized ylides and different aldehydes, we noted that the stereochemical outcome driving toward Z-olefin formation was influenced only by different steric factors. The proposed mechanism differs from those previously reported because it underlines the fundamental role of the two cis/trans oxaphosphetane intermediates with the oxygen atom in equatorial position.
WITTIG REACTION: ROLE OF STERIC EFFECTS IN EXPLAINING THE PREVALENT FORMATION OF Z OLEFIN FROM NONSTABILIZED YLIDES / G. Baccolini; C. Delpivo; G. Micheletti. - In: PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS. - ISSN 1042-6507. - STAMPA. - 187:(2012), pp. 1291-1302. [10.1080/10426507.2012.694000]
WITTIG REACTION: ROLE OF STERIC EFFECTS IN EXPLAINING THE PREVALENT FORMATION OF Z OLEFIN FROM NONSTABILIZED YLIDES
DELPIVO, CAMILLA;MICHELETTI, GABRIELE
2012
Abstract
For understanding the mechanism involved in the Wittig reaction, it is important to know the factors which influence the stability of 1,2-oxaphosphetane intermediates with pentacoordinate phosphorus; in these intermediates, the steric factor plays a predominant role. Studying the Wittig reaction between nonstabilized ylides and different aldehydes, we noted that the stereochemical outcome driving toward Z-olefin formation was influenced only by different steric factors. The proposed mechanism differs from those previously reported because it underlines the fundamental role of the two cis/trans oxaphosphetane intermediates with the oxygen atom in equatorial position.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
