Pinacol domino reactions

When alkyne TT-activation meets pinacol-type [l,2]-rearrangement On the invention of domino reactions for the synthesis of carbocycles and heterocycles 13SL1471. 

Starting from tetrahydrocyclopenta[f)]furan-2-one 342, enyne 343, the substrate for the domino reaction, was prepared in 12 steps and with an overall yield of 45%. Exposure of 343 to the electron-rich gold(I) complex (t-Bu)2P(o-biphenyl)AuCl at room temperature afforded cis-hydrindanone 344 in 78% yield as a single stereoisomer (Scheme 14.54). The postulated mechanism involved Au(I) activation of the alkyne to initiate the cationic olefin cyclization of 346 to give carbocation 347, which then underwent a pinacol rearrangement to the final product 344. An originally attempted Lewis acid-catalyzed domino Prins/pinacol rearrangement of... 

Scheme 14.S4 Overman s total synthesis of (+)-sieboldineA (345) applying a domino 1,6-enyne cyclization/pinacol shift reaction.

In 2013, Zhang and Qian developed an enantioselective domino redox-pinacol-Mannich reaction, allowing an easy entry to chiral spirocyclic... 

Scheme 7.39 Domino redox-pinacol-Mannich reaction catalysed by chiral phosphoric acid catalysis and gold catalysis.

Scheme 1.46. Domino pinacol rerrangement/ene-reaction strategy in the total synthesis of perhydrohistrionicotoxin (1-202a).

Quite recently, a domino Diels-Alder/Prins/pinacol reaction was reported by Barriaulfs group [38]. This novel method is very reliable and efficient for the synthesis of highly functionalized bicyclo[m.n.l]alkanones. In addition, Aube and coworker [39] used a combination of a Diels-Alder and a Schmidt reaction within the total synthesis of the Stemona alkaloid stenine [40]. 

Domino Diels-Alder/Prins/Pinacol Reactions... 

Barriault et al. demonstrated the Lewis acid-mediated triple domino Diels-Alder/ Prins/Pinacol reactions [22], which were utilized for the construction of highly functionalized bicyclo[m.n.l]alkanones [23]. Some tetra-fused carbocycles were efficiently produced from the corresponding cycloadducts generated in situ by the Diels-Alder reaction of 2,2-dimethyl-1,3-dioxolanes having a diene moiety at C4 position with dienophiles (Scheme 10.6). 

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