320618-85-7

Upstream product

• 4530-20-5 BOC-glycine 
• 320618-66-4 1-bromo-2-(dimethylphenylsilanyl)but-2(E)-ene 
• 31954-27-5 N-(tert-butoxycarbonyl)glycine methyl ester 
• 320618-65-3 (Z)-2-(phenyldimethylsilyl)but-2-en-1-ol 
• 101150-39-4 E-1-iodo-1-(dimethylphenylsilyl)propene 
• 320618-86-8 N-tert-butoxycarbonyl-N-[2-(dimethylphenylsilanyl)but-2(Z)-enyl]glycine methyl ester 

Downstream Products

• 320618-92-6 N-methoxy-N-methyl-[N-tert-butoxycarbonyl-N-(2-phenyldimethylsilylbut-2(Z)-enyl)amino]acetamide 
• 864360-79-2 [2-(dimethylphenylsilanyl)-but-2-enyl]-[2S]-[2-[2-(hydroxydiphenylmethyl)-pyrrolidin-1-yl]-2-oxo-ethyl]-carbamic acid tert-butyl ester 
• 864360-73-6 [N-tert-butoxycarbonyl-[2-(dimethylphenylsilanyl)-but-2-enyl]-amino]-acetic acid [1R,2S]-2-phenyl-cyclohexyl ester 
• 864360-77-0 [2-(dimethylphenylsilanyl)-but-2-enyl]-[2S]-[2-(2-hydroxymethylpyrrolidin-1-yl)-2-oxo-ethyl]-carbamic acid tert-butyl ester 
• 864360-81-6 [N-tert-butoxycarbonyl-[2-(dimethylphenylsilanyl)-but-2-enyl]-amino]-acetic acid [1S,5R]-2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-3-yl)-ethyl ester 
• 864360-67-8 [2S,3R]-2-N-tert-butoxycarbonyl-amino-4-(dimethylphenylsilanyl)-3-menthylpent-4-enoic acid [1R,2S,5R]-8-phenylmenthol ester 

Relevant academic research and scientific papers

Asymmetric aza-[2,3]-Wittig sigmatropic rearrangements: Chiral auxiliary control and formal asymmetric synthesis of (2S, 3R, 4R)-4-hydroxy-3- methylproline and (-)-kainic acid

A survey of 16 different chiral auxiliaries and a variety of strategies found that an (-)-8-phenylmenthol ester of a glycine derived migrating group can control the absolute stereochemistry of aza-[2,3]-Wittig sigmatropic rearrangements with diastereoselectivities of ca. 3 : 1 with respect to the auxiliary. In two specific examples, ca. 50% yields of enantiomerically pure products were obtained after chromatographic purification. These were synthetically manipulated with no erosion of stereochemistry into intermediates that completed formal asymmetric syntheses of (+)-HyMePro and (-)-kainic acid. The Royal Society of Chemisrry 2005.

The aza-[2,3]-Wittig sigmatropic rearrangement of acyclic amines: Scope and limitations of silicon assistance

The inclusion of a C-2 trialkylsilyl substituent into allylic amine precursors allows the base-induced aza-[2,3]-Wittig sigmatropic rearrangement to proceed in excellent yield and diastereoselectivity. The rearrangement precursors require a carbonyl-based nitrogen protecting group that must be stable to excess of strong base required for the reaction. The N-Boc and N-benzoyl group are very good at stabilizing the product anion and initiating deprotonation. The migrating groups (G) need to stabilize the intial anion by resonance and require G-CH3 pKa > 22 in order for the initial anion to be reactive enough for rearrangement. Products 7, 29b-d,f,g, and 23 are formed with high (10-20:1) anti diastereoselectivity. Product 23 containing the morpholine amide group is useful for preparing other carbonyl derivatives.