169324-82-7Relevant articles and documents
In situ enzymatic screening (ISES): A tool for catalyst discovery and reaction development
Berkowitz, David B.,Bose, Mohua,Choi, Sungjo
, p. 1603 - 1607 (2007/10/03)
Can enzymes help organic chemists identify new transition-metal catalysts? The first example of the in situ enzymatic monitoring of an organic transformation is described. Thus, a transition-metal-mediated allylic-amination reaction in the organic layer (
Fe(II)-catalyzed imidation of allyl sulfides and subsequent [2,3]- sigmatropic rearrangement. Preparation of α-branched N-tert-butyloxycarbonyl (Boc)-protected N-allylamines
Bach, Thorsten,Koerber, Christina
, p. 2358 - 2367 (2007/10/03)
Allyl aryl sulfides 1 and 5 were shown to undergo an imidation/[2,3]- sigmatropic rearrangement reaction upon treatment with N-tert- butyloxycarbonyl azide (BocN3) and catalytic amounts of FeCl2 in CH2Cl2. The N-Boc-protected N-allyl sulfenamides 3 and 21 were obtained in yields between 48 and 75% (12 examples). Whereas the reaction is well suited for the transformation of α-unbranched sulfides to α-branched sulfenamides, the enantiomerically pure α-branched sulfides 10 and 13 reacted sluggishly. The corresponding sulfenamides 22 and 23 were obtained in only moderate enantiomeric excess (36-39% ee). A reaction mechanism is proposed that postulates the intermediacy of an N-Boc-substituted Fe(IV)-nitrene complex 14 acting as the imidation reagent in the catalytic cycle. Possible side reactions are discussed. The benzenesulfenamides 3 were further converted into N-Boc-N-allylamines 4 by removal of the phenylsulfanyl group. Bu3SnH in benzene was found to be the reagent of choice for the deprotection of α- branched amines that bear a secondary allyl substituent (five examples, 71- 93% yield). This method failed for the α-branched amines 3i-k with a tertiary allyl substituent. The phenylsulfanyl group was finally removed with P(OEt)3/NEt3 in CH2Cl2 (three examples, 43-62% yield).
