摘要:
The subject matter of the present invention relates to a reagent and a process useful for cleaving a functional group protected by an alkoxycarbonyl group during an organic synthesis. This reagent comprises: a) an aqueous phase; b) a catalyst comprising at least one group VIII element in the periodic table of elements and at least one water-soluble ligand, wherein the group VIII element in the periodic table is maintained in the aqueous phase by the formation of a complex with at least one water-soluble ligand; and c) a nucleophilic compound soluble in the aqueous phase; and optionally d) an organic phase.
摘要:
Dansylethoxycarbonyl (Dans-EOC) groups which can be employed as base-labile 5'hydroxyl protective groups in chemical oligonucleotide synthesis are disclosed. These groups allow the preparation of a compound of the formula (I) ##STR1## which comprises reacting the compound of the formula (II) ##STR2## with a chlorocarbonyl donor.
摘要:
A technique for the synthesis of arrays of diverse polymers such as polypeptides and nucleic acids. The technique beneficially utilizes solid-phase chemistry techniques. Preferred embodiments utilize photolabile protecting groups, and photolithography. The technique forms polymers with monomer sequences and locations determined by the order of addition of monomers and the activation patterns formed on the substrate.
摘要:
The invention relates to a process for the resolution of enantiomers of 5-heteroaryl-1,3,4-thiadiazinones of formula I by the kinetic resolution of racemates, characterized in that racemic I is dissolved in an inert solvent or solvent mixture and acylated with a chiral acid chloride. The resulting mixture of diastereoisomers is reacted with an amine or alcohol, thereby achieving a complete resolution of one of the diastereoisomers and a very slight or partial resolution of the other diastereoisomer into the enantiomers on which they are based, the resolution products are then separated off and the remaining pure diastereoisomer is converted to the corresponding pure enantiomer by reaction with an amine or an alcohol.
摘要:
Compounds of the formula Ia ##STR1## in which X and R.sup.1 to R.sup.6 are as defined in the claims, are obtainable by reacting monochlorosilanes of the formula II ##STR2## with tetrasubstituted ethylenes of the formula III ##STR3## X as Cl and Br can be replaced by ester groups of inorganic and organic acids. The compounds of the formula I and those with other ester groups are suitable especially as a protective-group reagent for hydroxyl, mercapto, carboxyl, amino and amide groups.
摘要:
An improved synthetic process for the removal of an allyl group in an allylic ester or an allyloxycarbonyl group in an allylic carbonate or carbamate by reaction with 2-ethylhexanoic acid or an alkali metal salt thereof and a catalytic amount of an organic-soluble palladium complex is disclosed herein.
摘要:
A process for the separation and/or purification of oligo- and polyhydroxy compounds by introducing and subsequently eliminating protective groups, wherein oligo- and polyhydroxy compounds are reacted with bis(ethyl-pivaloyloxy)-diboroxane or ethylboroxine, optionally in inert solvents, the resulting O-ethylboranodiyl derivatives of the hydroxy compounds are separated off and the O-ethylboranodiyl protective groups are eliminated by alcoholic compounds, for example methanol or glycol.
摘要:
Provided herein are immobilized chiral phosphoric acids and methods of using immobilized chiral phosphoric acids as catalysts for protecting group reactions.
摘要:
Disclosed herein is a method of forming a compound of formula I: wherein the substituents are defined in the specification. In particular, the compounds of formula I can be converted to amino acids bearing quaternary stereocenters with exceptional optical purities.
摘要:
An object of the present invention is to develop a protecting group, which can prevent solidification or insolubilization of a compound by protecting a functional group to achieve easy separation and purification after a reaction. A diphenylmethane compound represented by general formula (1): wherein Y represents —OR19 (wherein R19 represents a hydrogen atom or an active ester-type protecting group), —NHR20 (wherein R20 represents, for example, a hydrogen atom, a C1-6 linear or branched alkyl group, or an aralkyl group, at least one of R1 to R10 represents a group represented by formula (2): —O—R11—X-A (2) and the others each independently represent a hydrogen atom, a halogen atom, a C1-4 alkyl group, or a C1-4 alkoxy group; R11 represents a C1-16 linear or branched alkylene group; X represents O or CONR21 (wherein R21 represents a hydrogen atom, or a C1-4 alkyl group; and A represents, for example, a group represented by formula (3).