Dihalohydration of Alkynols: A Versatile Approach to Diverse Halogenated Molecules.

In this paper we outline how dihalohydration reactions of propargylic alcohols can be used to access a wide variety of useful halogenated building blocks. A novel procedure for dibromohydration of alkynes has been developed, and a selection of dichloro and dibromo diols and cyclic ethers were synthesized. The dihalohydration of homo-propargylic alcohols provides a useful route to 3-halofurans, which were shown to readily undergo cycloaddition reactions under mild conditions. Finally, a novel ring expansion of propargylic alcohols containing a cyclopropylalkyne provides access to halogenated alkenylcyclobutanes.

Intercepting the Gold-Catalysed Meyer-Schuster Rearrangement by Controlled Protodemetallation: A Regioselective Hydration of Propargylic Alcohols.

The regioselective gold-catalysed hydration of propargylic alcohols to ß-hydroxy ketones can be achieved by diverting the gold-catalysed Meyer-Schuster rearrangement through the addition of a protic additive with a pKa of 7-9 such as p-nitrophenol, boric acid or a boronic acid. This provides an interesting alternative to an aldol reaction when combined with the straightforward addition of an alkyne to an aldehyde or ketone. The gold-catalysed reaction of an electron-deficient, sterically hindered propargylic alcohol with a boronic acid led to the formation of an unusually stable cyclic boron enolate.

Expanding the scope of N → S acyl transfer in native peptide sequences.

Understanding the factors that influence N → S acyl transfer in native peptide sequences, and discovery of new reagents that facilitate it, will be key to expanding its scope and applicability. Here, through a study of short model peptides in thioester formation and cyclisation reactions, we demonstrate that a wider variety of Xaa-Cys motifs than originally envisaged are capable of undergoing efficient N → S acyl transfer. We present data for the relative rates of thioester formation and cyclisation for a representative set of amino acids, and show how this expanded scope can be applied to the production of the natural protease inhibitor Sunflower Trypsin Inhibitor-1 (SFTI-1).

A lactate-derived chiral aldehyde for determining the enantiopurity of enantioenriched primary amines.

In this paper we describe the use of a chiral aldehyde derived from lactate esters for determining the enantiopurity of primary amines, via the formation of diastereomeric imines. The method was shown to be suitable for reproducibly determining the enantiopurity of a diverse set of chiral amines. Both enantiomers of the aldehyde can be prepared in two steps from commercially available materials.

Why did I right that? Factors that influence the production of homophone substitution errors.

Despite considerable research on language production errors involving speech, little research exists in the complementary domain of writing. Two experiments investigated the production of homophone substitution errors, which occur when a contextually appropriate word (e.g., beech) is replaced with its homophone (e.g., beach tree). Participants wrote down auditorily presented sentences containing dominant or subordinate homophones. Homophones were preceded by a lexical prime that overlapped in phonology and orthography (e.g., teacher) or only orthography (e.g., headmaster) with the target homophone. Results showed more substitution errors when the context elicited a subordinate homophone than when it elicited a dominant homophone. Furthermore, both types of primes equivalently increased production of homophone errors relative to control words (e.g., lawyer), suggesting that only orthographic overlap between the prime and target was necessary to influence errors. These results are explained within dual-route models of spelling, which postulate an interaction between lexical and sublexical routes when spelling.