Design and Synthesis of Diversely Substituted Azacyclic Inhibitors of Endothelin Converting Enzyme

Stereocontrolled Synthesis of Phosphoproline Analogues Containing a trans-Fused Octahydroindole Bicyclic System

Herein we report for the first time the diastereoselective synthesis of (2R,3aR,7aS)- and (2S,3aS,7aR)-octahydroindole-2-phosphonic acid (OicP trans-fused stereoisomers) from diethyl (R)- and (S)-phosphopyroglutamate derivative. The key steps of this procedure are the ruthenium tetroxide oxidation of enantiomerically pure diethyl (R)- and (S)-phosphoprolinate obtained through Katritzky's benzotriazole-oxazolidine methodology, a highly diastereoselective successive double 4,5-diallylation of diethyl (R)- and (S)-phosphopyroglutamate with allyl bromide and allyltrimethylsilane with a trans-addition mode, and a ring-closing metathesis with Grubbs' first-generation ruthenium catalyst.

Total Synthesis of the Proposed Structure of Penasulfate A: l-Arabinose as a Source of Chirality

The total synthesis of putative penasulfate A was effectively achieved by a convergent strategy with a longest linear sequence of 14 steps and overall yield of 8.6%. The highlights of our strategy involved an E-selective olefin cross-metathesis, Suzuki cross-coupling, and a copper(I)-catalyzed coupling reaction.

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

The conjugate addition reaction has been a useful tool in the formation of carbon-carbon bonds. The utility of this reaction has been demonstrated in the synthesis of many natural products, materials, and pharmacological agents. In the last three decades, there has been a significant increase in the development of asymmetric variants of this reaction. Unfortunately, conjugate addition reactions using α,β-unsaturated amides and lactams remain underdeveloped due to their inherently low reactivity. This review highlights the work that has been done on both diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams.

An Overview of Stereoselective Synthesis of α-Aminophosphonic Acids and Derivatives

An overview of all methodologies published during the last few years focused to the stereoselective (diastereoselective or enantioselective) synthesis of α-aminophosphonic acids and derivatives is reported. The procedures have been classified according a retrosynthetic strategy and taking into account the formation of each one of the bonds connected to the chiral centre.

Three-Component Reactions with (S)-Methyl Pyroglutamate: An Efficient Way to Diversely Substituted Asymmetric Amidocyclohexenes

Chiral N-dienyl lactams are crucial building blocks for the synthesis of complex organic compounds. However, their generation is rather challenging. This paper reports the novel one-pot reaction of (S)-methyl pyroglutamate as the amide component with different aldehydes and dienophiles (AAD reaction) to give novel chiral 1-amido-2-cyclohexenes. The corresponding N-dienyl lactams generated in situ undergo subsequent Diels-Alder reactions in good yield and diastereoselectivity. The scope and limitations of the three-component protocol were investigated. X-ray and NMR spectroscopic analysis of the products as well as DFT calculations of the intermediates were also performed to explain the observed stereoselectivity and structural features.