The metal-ligand complexes of Cu(OTf)2 with an appropriate bisphosphine ligand have been shown to effectively catalyze the formation of substituted tetrahydropyrans via a sequential olefin migration and Prins-type cyclization. This methodology provides convenient access to a variety of functionalized tetrahydropyrans in excellent diastereoselectivities and good to excellent yields.

It is reported that appropriate dienolborinates can provide access to both diastereomers of 2-(hydroxymethyl)but-3-enoates through exclusive α-regiocontrol in a non-vinylogous pathway. Contrary to previous reports in which dialkylchloroboranes failed to enolize propanoates, acidity-enhanced but-3-enoates readily undergo enolization, offering unprecedented control over the formation of these valuable synthons. The first example of an aldol reaction in the presence of a phosphine-borane adduct is also reported.

No abstract

The use of tetrabutylammonium hydroxide as a novel and exceedingly efficient thia-Michael addition catalyst is herein described. This extremely simple methodology allows for the conjugate addition of a wide variety of mercaptan nucleophiles, and functions remarkably well with a very wide range of both classical and non-classical Michael acceptors. Contradistinctive to current literature reports, the use of this catalyst more efficiently promotes the addition of more basic thiols. This methodology is especially attractive and operationally simple, as it generally proceeds with only 1 mol% catalytic loading and without excess reagent, and the produced products typically require no purification.

No abstract

An auto-catalytic domino reaction, presumably involving an aza-Michael reaction, proton transfer, and lactonization, furnishing α-(aminomethyl)-γ-butyrolactones in near quantitative yields and excellent diastereoselectivity is described.

No abstract

No abstract