Organic electrophiles organostannane

The late Professor J. K. Stille pioneered the development of a very effective and versatile palladium-mediated C-C bond forming method - the palladium-catalyzed cross-coupling of organic electrophiles with organostannanes.48 This process continues to enjoy much success in organic synthesis because it proceeds in high yields under mild reaction conditions and because it tolerates a... 

The extensive synthetic and mechanistic work carried out by Stille [12, 13] established this reaction as a mature synthetic method for organic synthesis [40, 52, 53). In the first comprehensive mechanistic proposal, a [PdLjj (L= PPh,) complex was proposed to react with the organic electrophile R-X to form complex 1 (Scheme 1.2). Complex 1 was the only observable species in the catalytic cycle, even in the presence of excess organostannane, which demonstrated that the slow step is the... 

The cross-coupling of organic electrophiles with organostannanes, commonly known as the Stille reaction, is one of the most versatile and selective palladium-catalyzed cross-coupling reactions [190]. Today, the Stille reaction is found among the routinely performed transformations in organic chemistry when it comes to... 

The Stille reaction [41] is a general, selective, and multifaceted palladium-catalyzed reaction used to construct C—C bonds [42]. It proceeds via Pd-catalyzed coupling of organic electrophiles such as unsaturated halides, sulfonates, or triflates with functionalized organostannanes. Although it is nowadays considered a standard method in organic synthesis, recent modifications and variants of the Stille reaction have opened up a multitude of new and highly attractive synthetic possibilities. 

The reaction between an organic electrophile 1 and an organostannane 2 mediated by a transition metal catalyst (originally palladium) to form a new sigma carbon carbon bond is referred to as the Stille cross-coupling reaction (equation 1). 

If using a palladium(Il) catalyst, the catalytic active species palladium(O) 9 is generated in situ from reduction of the palladium(II) precursor with the organostannane present in the medium. Oxidative addition of the organic electrophile then generates a 16-electron palladium(Il) complex intermediate 10, which then undergoes a transmetalation step to... 

Solid Phase chemistry has also been used to help solving this problem by immobilizing one of the partners (organic electrophile or organostannane) on the solid support to help purification. An example of this approach is found in Nicolaou s total synthesis of (S)-zearalenone (43 — 44). 

Organostannane. Organic electrophiles usually unsaturated halides and triflates undergo a Pd catalyzed coupling reaction with organotin reagents in a reaction known as the Stille reaction (equation 49) (for reviews see references 154-156). 

The addition of cocatalytic amounts of Cul (or other Cu(I) salts) facilitates the efficient cross-coupling of many organic electrophiles and organostannanes which are otherwise difficult to couple and in many other reactions accelerates the rate or increases the yield (765-775). One effect of Cu is to scavenge free ligand... 

The Stille reaction involves the transition-metal-mediated cross-coupling of organostannanes with organic electrophiles. Generally, it is a mild and efficient way for the creation of C—C bonds, especially between Csp or Csp centers. The most significant disadvantage of the method is... 

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