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Aryl iodides that are unreactive toward various diaryliodonium triflates undergo metathesis reaction with λ 3 -iodanes based on a highly nucleofugal aryl iodide such as 2-iodothiophene. Examples of such reactive iodanes include phenyl(2-thienyl)iodonium triflate and bis-(2-thienyl)iodonium triflate. This observation provides support for a mechanistic hypothesis advanced earlier.

A catalyst consisting of 1 mol % of the 1:2 complex of Pd(OAc)2 with N-(4-carbethoxyphenyl)urea promotes the Heck arylation of 2- or 3-substituted, conjugated esters, nitriles, aldehydes, and ketones (an uncharacteristically broad range of substrates), but only with electron-rich aryl iodides (an uncharacteristically narrow range of halides).

The oxidative amidation of phenols effects the conversion of appropriately substituted phenols into 4-amidodienones (‘ para -oxidative amidation’) or 2-amidodienones (‘ ortho -oxidative amidation’) by the action of hypervalent iodine reagents. The reagent, (diacetoxyiodo)benzene (‘DIB’) is especially effective in these transformations. This paper focuses on techniques for the desymmetrization of the dienoes thus obtained, leading to the stereocontrolled creation of N -substituted spiro carbons. The methodology creates new opportunities in alkaloid synthesis, as apparent from a number of examples.

We describe the development of a technique for the oxidative conversion of 4-alkyl phenols to derivatives of the corresponding 4-alkyl-4-amino-2,5-cyclohexanediones. This transformation, which was inspired by biogenetic considerations, constitutes a key step in the total syntheses of FR-901483, TAN-1251C, and cylindricine C.

A catalytic ene-like reaction of aldehydes with those vinyl ethers that display the oxygen functionality at the central carbon of an allylic system, e.g., 2-methoxypropene, is discussed in detail. The reaction is promoted by 0.05 equiv. of the 1:1 complex of Yb(fod)3 and acetic acid, and it is forms the centerpiece of our synthesis of chlorovulone II, mitomycinoids and phyllanthocin.

The evolution of our strategy for the synthesis of (+)-Camptothecin and related substances is presented in detail.