Studies on Catalytic Asymmetric Nozaki−Hiyama Propargylation

Catalytic asymmetric Nozaki−Hiyama propargylation with ligand 1c proceeds with good to excellent enantioselectivity. Tuning of ligand 1 dramatically changes the enantioselectivity, and we propose models A and B to explain the change and outcome of the enantioselectivity

Correction to Enantioselective Total Synthesis of (+)-Colletoic Acid via Catalytic Asymmetric Intramolecular Cyclopropanation of an α‑Diazo-β-keto Diphenylphosphine Oxide

Correction to Enantioselective Total Synthesis of (+)-Colletoic Acid via Catalytic Asymmetric Intramolecular Cyclopropanation of an α‑Diazo-β-keto Diphenylphosphine Oxid

Synthetic Studies on (+)-Ophiobolin A: Asymmetric Synthesis of the Spirocyclic CD-Ring Moiety

Asymmetric synthesis of the spirocyclic CD-ring moiety of (+)-ophiobolin A is described. Fragment A, which was prepared via pig liver esterase (PLE)-mediated kinetic resolution, and fragment B, which was prepared via diastereoselective allylation and subsequent kinetic iodolactonization, were coupled to afford the allylsilane 2, which was successfully cyclized to the desired spirocyclic CD-ring moiety 1a in the presence of a Lewis acid

Structure Elucidation and Enantioselective Total Synthesis of the Potent HMG-CoA Reductase Inhibitor FR901512 via Catalytic Asymmetric Nozaki−Hiyama Reactions

The structure elucidation and enantioselective total synthesis of the potent HMG-CoA reductase inhibitor FR901512 were accomplished. FR901512 was prepared in 15 steps from the commercially available 2-bromo-4-methylbenzaldehyde via FR901516 in 16.3% overall yield (89% average yield). The catalytic asymmetric Nozaki−Hiyama reactions developed by us proved their applicability and reliability through this work, enabling the concise, efficient, and protecting-group-free enantioselective total syntheses of these new statins

A Non-Heme Iron(III) Complex with Porphyrin-like Properties That Catalyzes Asymmetric Epoxidation

In this report, we describe an iron­(III) complex containing a carbazole-based tridentate ligand that catalyzes highly enantioselective asymmetric epoxidation of (E)-alkenes at room temperature. The non-heme iron­(III) complex has a five-coordinated trigonal-bipyramidal structure, and its two-electron oxidized state has the similar electronic structure as that of iron porphyrins

Synthetic Studies on (+)-Ophiobolin A: Asymmetric Synthesis of the Spirocyclic CD-Ring Moiety

Asymmetric synthesis of the spirocyclic CD-ring moiety of (+)-ophiobolin A is described. Fragment A, which was prepared via pig liver esterase (PLE)-mediated kinetic resolution, and fragment B, which was prepared via diastereoselective allylation and subsequent kinetic iodolactonization, were coupled to afford the allylsilane 2, which was successfully cyclized to the desired spirocyclic CD-ring moiety 1a in the presence of a Lewis acid

Biomimetic Total Synthesis of (−)-Erinacine E

Biomimetic total synthesis of (−)-erinacine E (1) has been achieved starting from the enantiopure key intermediate, which was prepared via the convergent approach developed by us. The crucial step in this synthesis is an intramolecular aldol reaction driven by the 1,2-migration of a benzoyl group within a compound that was rationally designed to prevent the retro-aldol reaction, thereby successfully providing the strained skeleton of 1. Considering the structure of a putative biosynthetic intermediate, striatal A, the intramolecular aldol reaction driven by the C4‘ acetyl group could be involved in the biosynthesis of 1. This acyl group migratory ring-closing reaction could be applied to the synthesis of other strained molecules

Structure Elucidation and Enantioselective Total Synthesis of the Potent HMG-CoA Reductase Inhibitor FR901512 via Catalytic Asymmetric Nozaki−Hiyama Reactions

The structure elucidation and enantioselective total synthesis of the potent HMG-CoA reductase inhibitor FR901512 were accomplished. FR901512 was prepared in 15 steps from the commercially available 2-bromo-4-methylbenzaldehyde via FR901516 in 16.3% overall yield (89% average yield). The catalytic asymmetric Nozaki−Hiyama reactions developed by us proved their applicability and reliability through this work, enabling the concise, efficient, and protecting-group-free enantioselective total syntheses of these new statins

Synthetic Studies on (+)-Ophiobolin A: Asymmetric Synthesis of the Spirocyclic CD-Ring Moiety

Asymmetric synthesis of the spirocyclic CD-ring moiety of (+)-ophiobolin A is described. Fragment A, which was prepared via pig liver esterase (PLE)-mediated kinetic resolution, and fragment B, which was prepared via diastereoselective allylation and subsequent kinetic iodolactonization, were coupled to afford the allylsilane 2, which was successfully cyclized to the desired spirocyclic CD-ring moiety 1a in the presence of a Lewis acid

Enantioselective Total Synthesis of (+)-Colletoic Acid via Catalytic Asymmetric Intramolecular Cyclopropanation of an α‑Diazo-β-keto Diphenylphosphine Oxide

The enantioselective total synthesis of (+)-colletoic acid, a potent naturally occurring 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitor, is described. This total synthesis features a highly enantioselective catalytic asymmetric intramolecular cyclopropanation of an α-diazo-β-keto diphenylphosphine oxide and five highly stereoselective reactions (cyclopropane opening, Diels–Alder reaction, iodolactonization, alkene formation, and reduction of α,β-unsaturated carboxylic acid)