Regioselective Rh(I)-Catalyzed Sequential Hydrosilylation toward the Assembly of Silicon-Based Peptidomimetic Analogues

Abstract

A highly regioselective Rh(I)-catalyzed hydrosilylation of enamides is presented. This mild protocol allows access to a wide variety of different arylsilanes with substitution at the β-position of the enamide and functionalization on the alkyl chain tethered to the silane. This protocol is extended to include a sequential one-pot hydrosilylation. Using diphenylsilane as the appendage point, hydrosilylation of a protected allyl alcohol followed by hydrosilylation of an enamide generates a complex organosilane in one step. This highly convergent strategy to synthesize these functionalized systems now provides a way for the rapid assembly of a diverse collection of silane-based peptidomimetic analogues.

Total Synthesis of the Marine Natural Product Parazoanthine F by Copper‐Mediated C–N Coupling

“…Buchwald and coworkers had published a CuI/DMEDA-catalyzed C-N coupling of vinyl bromides and iodides with simple primary or cyclic secondary amides or carbamates (DMEDA = N,NЈ-dimethylethylenediamine). [13] For the synthesis of parazoanthine F (5), the coupling partner had to be vinyl bromide 19, which was synthesized by a Hunsdiecker reaction from O-methyl-p-coumaric acid. [13] For the synthesis of parazoanthine F (5), the coupling partner had to be vinyl bromide 19, which was synthesized by a Hunsdiecker reaction from O-methyl-p-coumaric acid.…”

“…At 0°C, this solution was added dropwise to a mixture of l-arginine methyl ester hydrochloride (2.340 g, 8.90 mmol, 1.0 equiv.) 1 13 Amino ({3-[(4S)-1-(2-(4-methoxyphenyl) 1.0 equiv. in DMF (10 mL).…”

“…NH* + ) ppm 13. C NMR (100 MHz, [D 4 ]methanol): δ = 176.3 and 176.1 [2 C, CH 2 N(CO)CH], 161.0 (2 C, C q OCH 3 ), 159.3 [2 C, N(CO)NH], 158.7 [2 C, NH 2 (CNH)NH], 135.0 [2 C, CHC q CH(OH)CH 2 ], 128.8 [4 C, CHC q CH(OH)CH 2 ], 114.8 (4 C, C HC q OCH 3 ), 71.4 [2 C, CHC q C H( OH )C H 2 ], 57 .7 [2 C, CH 2 N(CO)CH], 55.7 (2 C, OCH 3 ), 46.4 [1 C, CHC q CH(OH)CH 2 ], 46.2 [1 C, CHC q CH(OH)CH 2 ], 42.0 (2 C, CH 2 CH 2 CH 2 NH), 29.6 (2 C, CH 2 CH 2 CH 2 NH), 25.1 (1 C, CH 2 CH 2 CH 2 NH), 25.78 [t, J = 6.0 Hz, 1 H, CHC q CH(OH)CH 2 *], 4.00-3.96 [m, 2 H, N(CO)NHCH* + ], 3.72 (2 s, 6 H, C q OCH 3 * + ), 3.51 [ddd, J = 7.4, J = 8.1, J = 13.4 Hz, 2 H, CHC q CH(OH)CH 2…”

Copper‐Catalyzed β‐Iodovinylation of Carbamates: Expedient Access to Highly Functionalized Vinyl‐Carbamates

“…Vinyl carbamates are versatile synthetic intermediates which can be converted into pyrroles, pyrrolidines, amido indenes, peptidomimetic analogues, non‐natural amino acids precursors, and can also be used as imine surrogates. Moreover, vinyl carbamates can undergo nucleophilic addition with a variety of nucleophiles under copper or scandium catalysis …”

Isomerization of N-Allyl Amides To Form Geometrically Defined Di-, Tri-, and Tetrasubstituted Enamides

“…There is a single report of using Cu catalysis for the coupling of Z-propenyl bromide with amides but requires 24h at 100 °C and gives only moderate yields. 25 The base mediated isomerization of allyl benzamide ( 3a ) has been reported to give a 1:1 mixture of E:Z isomers. 24b The alternative hydroamidation of terminal alkynes for the synthesis of Z-enamides has not been applied to propenyl systems.…”