2652-46-2

Upstream product

• 1025801-25-5 Triethyl-[3-(tetrahydro-pyran-2-yloxy)-prop-1-ynyl]-silane 
• 50-00-0 formaldehyd 
• 1777-03-3 2-triethylsilylacetylene 
• 994-30-9 triethylsilyl chloride 
• 5582-62-7 1-trimethylsilyloxy-2-propyne 
• 107-19-7 propargyl alcohol 

Downstream Products

• 225656-81-5 diphenyl (3-(triethylsilyl)prop-2-yn-1-yl)phosphate 
• 131365-11-2 (3-bromo-1-propynyl)tert-butyldimethylsilane 
• 71572-60-6 3-triethylsilyl-2-propynal 
• 1392486-63-3 C₂₄H₄₀OSi₂ 
• 1256452-00-2 C₂₂H₄₀OSi₂ 
• 1256451-91-8 C₂₂H₃₈O₂Si₂ 
• 79746-17-1 1-triethylsilyloxy-but-1,3-diene 

Relevant academic research and scientific papers

Ni-catalyzed direct carboxylation of propargylic alcohols with carbon dioxide

The carboxylation of propargylic alcohols containing a silyl group at the terminal position was conducted in a CO2 atmosphere at atmospheric pressure in the presence of a nickel catalyst and diethylzinc. Here, CO2 was used as not only the C1 source but also the promoter of the COH cleavage processes for the oxidative addition of propargylic alcohols.

Total Synthesis and Stereochemical Assignment of Streptide

Streptide (1) is a peptide-derived macrocyclic natural product that has attracted considerable attention since its discovery in 2015. It contains an unprecedented post-translational modification that intramolecularly links the β-carbon (C3) of a residue 2 lysine with the C7 of a residue 6 tryptophan, thereby forming a 20-membered cyclic peptide. Herein, we report the first total synthesis of streptide that confirms the regiochemistry of the lysine-tryptophan cross-link and provides an unambiguous assignment of the stereochemistry (3R vs 3S) of the lysine-2 C3 center. Both the 3R and the originally assigned 3S lysine diastereomers were independently prepared by total synthesis, and it is the former, not the latter, that was found to correlate with the natural product. The approach enlists a powerful Pd(0)-mediated indole annulation for the key macrocyclization of the complex core peptide, utilizes an underdeveloped class of hypervalent iodine(III) aryl substrates in a palladium-catalyzed C-H activation/β-arylation reaction conducted on a lysine derivative, and provides access to material with which the role of streptide and related natural products may be examined.

Synthesis and Isolation of Organogold Complexes through a Controlled 1,2-Silyl Migration

During our efforts toward the synthesis of naturally occurring polyprenylated polycyclic acylphloroglucinol using a AuI-catalyzed 6-endo dig carbocyclization, we isolated stable vinyllic gold intermediates. Optimization lead to isolated yields of up to 98 %, using 2-(di-tert-butylphosphino)biphenyl as the ligand. This transformation is derived from a silyl rearrangement that can be fully controlled according to the nature of the substituent on the ynone. This selective transformation does not require basic conditions to prevent protodeauration. These vinylgold complexes are the first isolated intermediates during a silyl migration with gold(I). More than 16 new organogold complexes were synthesized and characterized by single-crystal X-ray diffraction. Reactivity of these complexes is also presented.

Synthesis of optically active ring-A substituted tryptophans as IDO inhibitors

The first synthesis of optically active 7-methoxy-d-tryptophan as well as other ring-A substituted tryptophans is described.

Efficient asymmetric synthesis of biologically important tryptophan analogues via a palladium-mediated heteroannulation reaction

A novel and concise synthesis of optically active tryptophan derivatives was developed via a palladium-catalyzed heteroannulation reaction of substituted o-iodoanilines with an internal alkyne. The required internal alkyne 14a or 25 was prepared in greater than 96% de via alkylation of the Schoellkopf chiral auxiliary 19 employing diphenyl phosphate as the leaving group. The Schoellkopf chiral auxiliary was chosen here for the preparation of L-tryptophans would be available from D-valine while the D-isomers required for natural product total synthesis would originate from the inexpensive L-valine (300-g scale). Applications of the palladium-catalyzed heteroannulation reaction were extended to the first asymmetric synthesis of L-isotryptophan 38 and L-benz[f]tryptophan 39. More importantly, the optically pure 6-methoxy-D-tryptophan 62 was prepared by this protocol on a large scale (>300 g). This should permit entry into many ring-A oxygenated indole alkaloids when coupled with the asymmetric Pictet-Spengler reaction. In addition, an improved total synthesis of tryprostatin A (9a) was accomplished in 43% overall yield employing this palladium-mediated process.

A direct and stereocontrolled route to conjugated enediynes

A unified synthetic route to 3-hex-en-1,5-diynes, a key building block found in many of the enediyne antitumor agents and designed materials, was developed. The method, which relies on a carbenoid coupling-elimination strategy is tolerant of a wide range of functionalities, and was applied to the synthesis of a variety of linear and cyclic enediynes. Reaction parameters can be adjusted to control stereoselectivity of the process, producing linear enediynes from 1:12 to >100:1 E:Z ratio, and in the case of cyclic enediynes, giving the exclusively Z C-9, C-10, or C-11 products. Key features of the process are the ready availability of precursors and the mildness and efficiency of the reaction. Application of the process in the design of materials precursors and preparation of enediyne antitumor agents are presented.

A route to enantiomerically-enriched α-silyl aldehydes from 2,3-epoxy alcohols

Asymmetric epoxidation of (E)-3-trialkylsilyl-2-propen-1-ols gives the expected epoxides with high enantioselectivity. Ring opening reactions of these epoxides with organocopper reagents furnishes 1,2-diols which are readily cleaved with Pb(OAc)4 to afford α-silyl aldehydes with no detectable loss of stereochemistry.

Stereochemical control in the metallohalocarbenoid route to linear enediynes

Methods for the stereoselective preparation and unmasking of disubstituted Z enediynes are reported. The origins of the unprecedented stereoselectivity of the process are uncovered.

Universal method for trimethylsilylation of acetylenic alcohols and glycols

A highly convenient universal method for trimethylsilylation of acetylenic alcohols and glycols via treatment by hexamethyldisilazane in the presence of benzoic acid sulphimide as a catalyst has been developed. The rate of trimethylsilylation of acetylenic alcohols is reduced from primary to secondary and to tertiary alcohols accordingly, as well as with the decreasing of hydroxyl nucleophylicity. The toxicity of trimethylsilyl acetylenic ethers, except 2-trimethylsiloxy-3-butyne, is much lower than that of original compounds.

Stereocontrolled synthesis of α-trialkylsilyl-β,γ-unsaturated aldehydes via palladium (0) catalysis synthetic usefulness

The reaction of silicon substituted vinyloxiranes in the presence of catalytic amount of palladium (0) catalyst affords the title compounds. This new reaction proceeds smoothly, under very mild conditions and with complete chirality transfer. One-pot addition of selected organometallic nucleophiles to these aldehydes at very low temperature led to a highly selective preparation of the corresponding alcohols in very good yields. Influence of substituents on the silicon atom and of the ligands of palladium have been studied.