NOVELTY - Preparation of beta -borated compound involves reacting substituted alkene compound with boronating agent in presence of water as solvent and a catalyst system comprising at least one copper atom in oxidation state (I) or (II) and at least one anion selected from carbonate, sulfate, nitrate, phosphate, hydroxide, acetate, tert-butoxide and/or oxide, where the reaction mixture is free of organic solvent.    USE - For preparation of beta -borated compound useful in the process of transformation of carbon-boron (C-B) bond to C-O, C-N, C-S bond and C-X bond (where X is F, CI, Br, I)(claimed); as intermediates in the synthesis of pharmaceutically active agents such as sitagliptin.    ADVANTAGE - The boronating agent and/or ligand allows obtaining (I') having an enantiomeric excess of at least 60% (preferably at least 85%, especially at least 98%). The chiral boronating agent and the chiral ligand are in enantiopure or diasteriomerically pure form. The process is a simple and environmentally benign process for preparation of beta -borated compounds. The method allows efficient and selective beta -boration of alkene compounds (Ia) and alkyne compounds (III) respectively. The beta -boration reaction can be carried out in a reaction mixture which is free of organic solvents, where reaction rate and/or conversion of the starting material is significantly improved compared to beta -boration reactions carried out in pure organic solvents or mixtures of organic solvents and water in which mixtures the amount of organic solvent predominates the amount of water. As an additional benefit, considerable amounts of harmful or even toxic organic solvents can be saved; preferably it can be dispensed with organic solvents. This in turn provides for a much more eco-friendly reaction medium compared to conventional beta -boration reactions in which typically pure organic solvents are applied as the solvent. Furthermore, the method provides considerably improved working conditions in a production process, since water is absolutely harmless for health, while the relatively volatile organic solvents are problematic in view of occupational exposure limits. Besides, as regards the catalyst system, it can be dispensed with toxic and/or expensive metal catalysts such as platinum, rhodium, palladium or nickel; and can be dispensed with a ligand which is typically applied in conventional beta -boration processes.    DETAILED DESCRIPTION - Preparation of beta -borated compound of formula (I') involves reacting substituted alkene compound of formula (Ia) with boronating agent having formula H-BR5R6 or R6R5-B-B-R5R6 in presence of water as solvent and a catalyst system comprising at least one copper atom in oxidation state (I) or (II), and at least one anion selected from carbonate (CO32-), sulfate (SO42-), nitrate (NO3-), phosphate (PO43-), hydroxide (OH-), acetate (OAc-), tert-butoxide (O-tBu-) and/or oxide (O2-), where the reaction mixture is free of organic solvent.    R1, R3 and R4=H, 1-12C alkyl, 6-24C aryl or 7-24C alkylaryl (all optionally substituted);    R2=1-12C alkyl, 6-24C aryl or 7-24C alkylaryl (all optionally substituted), formyl (-CO-H), oxoalkyl, oxoaryl or oxoalkylaryl (-CO-1-12C alkyl, -CO-6-24C aryl, -CO-7-24C alkylaryl) (v), alkyloxycarbonyl (-CO-O-1-12C alkyl), aryloxycarbonyl (-CO-O-6-24C aryl), alkylaryloxycarbonyl (-CO-O-7-24C alkylaryl) or vinyloxycarbonyl (-CO-O-CH=CH2) (vi), N-unsubstituted carbamoyl (-CO-NH2) or N-substituted carbamoyl (-CO-NR'R1a) (vii), cyano, alkylsulfonyl (-SO2-1-12C alkyl), arylsulfonyl (-SO2-6-24C aryl) or alkylarylsulfonyl (-SO2-7-24C alkylaryl);    R' and R1a=1-12C alkyl, 6-24C aryl or 7-24C alkylaryl;or    R2+R3 or R2+R4=5-8 membered monocyclic ring (preferably 5-6 membered ring, optionally including within the monocyclic ring any one of structural characteristics (v), (vi) and (vii));    R5 and R6=1-12C alkyl, 1-12C alkoxy, 6-14C aryl or 6-14C aryloxy (all optionally substituted) or halo;or    R5+R6=chiral or non-chiral 5-10 (preferably 5-6) membered mono or bicyclic ring (ring is optionally substituted at least one position with 1-12C alkyl and/or 6-14C aryl).    An INDEPENDENT CLAIM is included for preparation of boron compound of formula (IV) involving reacting substituted alkyne compound of formula R1b-C?=C-R2' (III) with boronating agent having formula H-BR5R6 or R6R5-B-B-R5R6 in presence of water as solvent and a catalyst system comprising at least one copper atom in oxidation state (I) or (II), and at least one anion selected from carbonate (CO32-), sulfate (SO42-), nitrate (NO3-), phosphate (PO43-), hydroxide (OH-), acetate (OAc-), tert-butoxide (O-tBu-) and/or oxide (O2-), where the reaction mixture is free of organic solvent.    R1b=H, 1-12C alkyl, 6-24C aryl or 7-24C alkylaryl (all optionally substituted), alkyloxycarbonyl (-CO-O-1-12C alkyl) or aryloxycarbonyl (-CO-O-6-24C aryl);    R2'=6-24C aryl (optionally substituted).