Wittig without waste

Recycling the waste: the development of a catalytic wittig reaction.

Catalytic Wittig and aza-Wittig reactions

This review surveys the literature regarding the development of catalytic versions of the Wittig and aza-Wittig reactions. The first section summarizes how arsenic and tellurium-based catalytic Wittig-type reaction systems were developed first due to the relatively easy reduction of the oxides involved. This is followed by a presentation of the current state of the art regarding phosphine-catal...

Key Derivation without Entropy Waste

We revisit the classical question of converting an imperfect source X of min-entropy k into a usable m-bit cryptographic key for some underlying application P . If P has security δ (against some class of attackers) with a uniformly random m-bit key, we seek to design a key derivation function (KDF) h that allows us to use R = h(X) as the key for P and results in comparable security δ′ ≈ δ. Seed...

The Wittig Reaction

The Wittig Reaction

This so-called Wittig reaction has a number of advantages over other olefination methods; in particular, it occurs with total positional selectivity (that is, an alkene always directly replaces a carbonyl group). By comparison, a number of other carbonyl olefination reactions often occur with double-bond rearrangement. In addition, the factors that influence Eand Z-stereoselectivity are well un...