79597-48-1Relevant academic research and scientific papers
Synthetic Studies on Cyclocitrinol: Construction of the ABC Ring System Based on Epoxy-Nitrile Cyclization
Sato, Kazuto,Tanino, Keiji
supporting information, p. 674 - 678 (2021/01/21)
The stereoselective synthesis of a model compound containing the ABC ring system of cyclocitrinol was accomplished. After connecting a C ring allyltitanium segment with an A ring bi? cyclo[4.1.0]heptanone segment, the seven-membered B ring moiety was cons
Allylic nitro compounds as nitrite donors
Chakrapani, Harinath,Gorczynski, Michael J.,King, S. Bruce
, p. 16332 - 16337 (2007/10/03)
Allylic nitro compounds were synthesized and evaluated as organic sources of nitrite and nitric oxide. Unactivated allylic nitro compounds do not spontaneously release nitrite and nucleophile promoted nitrite release is slow. However, 2-(nitromethyl)-cycl
Silica gel catalysed generation of episulfonium ions: A mild method for the synthesis of heterocycles
Caggiano, Lorenzo,Fox, David J.,Warren, Stuart
, p. 2528 - 2529 (2007/10/03)
β-Carbonyloxy sulfides fragment when heated with silica or alumina to produce reactive episulfonium ion intermediates. Intramolecular activation of the leaving group and concurrent protection of a nitrogen or oxygen nucleophile via a cyclic carbamate or c
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).
Stereo- and Regio-chemical Control in Phenylthio Migration around Rings of Sizes 5-15
Hannaby, Malcolm,Judson, Philip,Warren, Stuart
, p. 2609 - 2614 (2007/10/02)
Acid-catalysed rearrangement of cyclic alcohols with neighbouring syn or anti phenylthio groups leads to allylic sulfides with endo- or exo-cyclic double bonds.Only the anti alcohols rearrange for ring sizes n=5-10 but the syn alcohol rearranges if n=12 o
Synthesis of Cyclic Allylic Sulphides (Ring Sizes 5-15) via Phenylthio Participation
Hannaby, Malcolm,Warren, Stuart
, p. 303 - 311 (2007/10/02)
Dehydration of β-phenylthio alcohols occurs with PhS participation unless stereochemistry prevents it.Without PhS participation, mixtures of allylic and vinylic sulphides are formed, but with PhS participation routes to three families of cyclic allylic su
Preparation of allylic lithium reagents with the allylic system partly incorporated into carbocyclic rings
Screttas, Constantinos G.,Smonou, Ioulia C.
, p. 143 - 152 (2007/10/02)
A new method is described for preparation of allylic type organolithiums in which two of the allylic system carbons form part of carbocyclic ring.It involves cleavage of the readily accessible allylic sulfides 1-phenylthiomethylcycloalkanes by the naphthalenelithium in tetrahydrofuran.Carbonation of the reagents has given mixtures of cycloalken-1-yl acetic acids and 2-methylecycloalkane carboxylic acids, the distribution of which is strongly dependent on the ring size; thus the proportion of cycloalkenyl acetic acid, the endocyclic olefinic product, increases sharply on going from C5 to C8 ring derivatives and then considerably less sharply on going from C8 to C10 at which point the carbonation reaction has a high selectivity.It is concluded that the site of attack in the allylic anion by CO2 is determined by the thermochemical stability of the product(s).
A Novel Method for Furan Annelation by the Regioselective Acylation of Allylic Sulfides via α-Silyl Intermediates
Hiroi, Kunio,Sato, Hiroyasu
, p. 811 - 814 (2007/10/02)
Aluminum chloride-catalyzed acylations of allylic phenyl sulfides 3 with acid chlorides 5 were carried out via α-silyl intermediates 4 to give γ-acylated vinylic sulfides 6 with complete regioselectivity.Treatment of the γ-acylated compounds with concentr
Acid-Catalyzed Regioselective Acylation of α-Silylallylic Sulfides and Its Application to a Novel Cyclopentannelation and Furan Annelation
Hiroi, Kunio,Sato, Hiroyasu,Chen, Lih-Ming,Kotsuji, Kumiko
, p. 1413 - 1426 (2007/10/02)
Introduction of a silyl group at the α-position of allylic sulfides, followed by the aluminum chloride-catalyzed reaction of the resulting α-silylallylic sulfides with acid chlorides resulted in regioselective acylation at the γ-position of the allylic system to give γ-acylated vinylic sulfides, chemically equivalent to 1,4-dicarbonyl compounds.Heating of the products in refluxing benzene with an equimolar amount of p-toluenesulfonic acid produced 2-cyclopentanone derivatives.Treatment of the acylated products with an equimolar amount of concentrated sulfuric acid gave α-phenylthiofuran derivatives.These procedures provide a novel method for cyclopentannelation and furan annelation.Keywords - α-silylallylic sulfide; acid chloride; aluminum chloride; acid-catalyzed acylation; vinylic sulfide; 2-cyclopentanone; α-phenylthiofuran; furan; cyclopentannelation; furan annelation
REARRANGEMENT OF CYCLIC ALCOHOLS WITH AN ADJACENT PHENYLTHIO (PhS-) GROUP: MIGRATION OF A PhS GROUP AROUND A RING.
Hannaby, Malcolm,Warren, Stuart
, p. 765 - 768 (2007/10/02)
PhS migratoin around rings (size 5-15) gives allyl sulphides with a regioselectivity wich varies with ring size.
